Getting to know GeoDia (jee-oh-DEE-uh): Frequently Asked Questions

General Questions

What's Geodia all about?

GeoDia is meant to be a teaching and learning tool for anyone interested in the material culture of the ancient Mediterranean world. It seeks to represent the spatial and temporal distribution of human activity in that area, roughly from the emergence of complex literate societies in the Middle East to the foundation of Constantinople as the eastern capital of the Roman Empire (so from the fourth millennium BC to ca. 330 AD, though a few sites have information from earlier or later periods). Its dataset consists of two basic elements: sites (defined as geographic points where long-term human activity has left visible remains) and events (defined as things that happened at a specific geographic location and at a single point in time in the past). To avoid visual confusion, the two units are viewed separately. Sites appear in the timeline as bars, events as points.

You can use this site as an interactive textbook, heavy on facts and light on interpretation. You can search or view material remains as they're usually presented in textbooks for archaeology and art-history classes, grouped together by culture or region. But you can also use the site to cut across the boundaries those textbooks usually impose -- to look at Greek and Near Eastern sites side-by-side, for example, or to see what's happening at specific sites during non-canonical periods (for instance, in Roman Athens, or Seleucid Babylon). And you can move back and forth between images, events and sites to see how those three things are related in time and space.

Why was GeoDia developed?

Disciplines that study the remains of the past, like archaeology and art history, organize information (events, objects, monuments) along three major axes: time, culture, and place. Along each axis, the information is often grouped by perceived connections and similarities: along the time axis, information is organized into "periods"; along the cultural axis, into recognizable historical or material "cultures" like "Greek" or "Egyptian"; and along the spatial axis, into geographic areas or regions. Presenting all three characteristics as they relate to one another within a visual framework may be the best means of conveying contextual information to a student. GeoDia was developed to help students make sense of the spatial, temporal, and visual complexity that characterizes the material culture of the the ancient Mediterranean world across several thousand years. It is also intended to help students contextualize material in time and space in as many ways as they like.

How do you define "culture" and "region"?

These are both very problematic concepts in Mediterranean archaeology. Without taking a position in the debate, we have used a lowest-common-denominator definition of "culture". We have tried to use the cultural terms and meanings that appear most commonly in introductory textbooks, to avoid confusion -- so our "Greek" should correspond to sites or objects identified as "Greek" in most art-history and archaeology courses and texts. At sites where more than one culture is represented, we have noted the presence of the two most recognizable cultures in the most common terms, so that these sites can be found by users searching for either term. This makes no statement about hybridity or any other theoretical construct of identity. It simply means that there is good evidence for the presence of people using material items associated with both those cultures at that site.

Our use of "region", on the other hand, is idiosyncratic. Since GeoDia attempts to highlight connections and communication, we have avoided a spatial definition that coincides either with the traditional "cultures" mentioned above or with modern national boundaries. Instead, we have defined regions as zones of communication, within which both ancient and modern peoples have been in close contact, sharing ideas, objects, and technologies. These regions are defined largely by physical connectivity, which in the Mediterranean is closely associated with sea and river travel. They tend to be divided, on the other hand, by mountains or deserts. Thus parts of modern Italy fall into four different "regions": the Adriatic basin; the Western Mediterranean, separated from the Adriatic coast by the Apennines; the Aegean, with which southern Italy and eastern Sicily communicate by sea; and North Africa, which is closely connected across history with western Sicily and Sardinia. Since our use of the term "region" does not correspond to many common uses, you may wish to consult our map before browsing.

How do you define "period"?

A "period" is a conventional term that historians, archaeologists, and art historians use to place groups of related events, objects, or styles within chronological boundaries. On the most basic level, a period has a name, a start date, and an end date. In reality, however, the concept is almost infinitely complex, and varies not only from country to country, but from scholar to scholar. We have broken the concept down into four component parts, which we have derived from published work, and then further distinguished between a general "period" that applies to many sites and a "custom" period that fits the chronology of a particular site.

The four attributes we have recognized are: a term or name ("Bronze Age", "Achaemenid"); an absolute date range (1200 BC-750 BC); a specific culture, the material remains of which are described by that term (for example, "Archaic" is a period term used to describe Greek culture, among others); and a region within which that period term usually has the same meaning in modern parlance. The resulting "period" is then associated with a given archaeological site, where it is assigned custom absolute dates that reflect the particular history of activity at that site (the "Flavian" period stops suddenly at Pompeii in 79 AD, for example). So, for example, we have a period called "Archaic" associated with "Greek" culture and located in "the Aegean". By default, this period runs from 650 BC to 480 BC. But at a Sicilian Greek site, the "Archaic" period might end in 450 BC, depending on the way scholars discuss the material remains. And it is distinct from another period called "Archaic" but associated with "Etruscan" culture, which might end at Rome in 509 BC, when the "Early Republican" period begins there.

Why do you use BC and AD, rather than BCE and CE?

The choice of calendrical format is dictated by the way dates are parsed by the Simile timeline script.

How does GeoDia work?

GeoDia uses faceted browsing to apply multiple search filters along different information axes, such as cultures, geographic regions, and chronological periods. Results are expressed using timemap.js, a mashup of the Google Maps API and an interactive timeline API (the Simile project, developed at MIT), combined with image resources from the Liberal Arts DASe (Digital Archive Services) project. For more specific information, you can visit the project's googlecode site (/ or the timemap.js site (

Where did the information in GeoDia come from?

The information about site location, periods, events, and images was drawn from a range of sources under the supervision of Adam Rabinowitz, a classical archaeologist at the University of Texas at Austin. Site locations were identified from available maps and online mapping resources by Professor Rabinowitz or by a team of graduate students in the departments of Classics and Art and Art History at UT Austin under his supervision. Professor Rabinowitz and Abbey Turner, one of these students, also gathered the period information that is associated with the sites, specifying the published source from which the chronological information was drawn wherever possible. We focused on site-level publications, so that we could represent the periodization and chronologies used by archaeologists working at those particular sites. Sites, events, images and periods continue to be added by Professor Rabinowitz or by students under his supervision. Information associated with images was either produced by Professor Rabinowitz and the student team, or drawn from an extensive Classics image database developed by former Classics IT specialist Constanze Witt.

How do I know I can trust the data?

We are making efforts to connect our information with other sources of information, especially with Uniform Resource Identifiers (URIs). So far, we have begun to connect the sites in GeoDia with the URIs provided by the Pleiades Project ( The Pleiades Project contains the geographic and historical information collected and published in the Barrington Atlas of Classical Antiquity, which was compiled by experts in the field. You can be very confident, therefore, about the accuracy of the location and identification of the sites in GeoDia (and you can check them in Pleiades).

The reliability of the period and image data in GeoDia is lower, however, for two reasons. One, it is more susceptible to error, simply from the sheer scale of the information involved. If you see an obvious error, please report it to us (see "Comments and Feedback", below). And two, there are often scholarly disagreements about relative and absolute chronologies, and about the date of individual objects or monuments. GeoDia derives its information from scholarly sources and strives to be as accurate as possible, but do NOT take it as an authoritative and fully fact-checked resource. If your information conflicts with ours, use your own. The GeoDia team is part of an ongoing discussion about the creation of period URIs for the ancient Mediterranean, and if such URIs are created, GeoDia will refer its users to them for authoritative statements about periods and chronologies. Until then, cite the information here at your own risk.

Where are the GeoDia data stored, and can I reuse them?

The data used to create the visualizations in GeoDia are stored in an instance of the open-source Digital Archive Services (DASe) infrastructure at the University of Texas at Austin (for more information, see They are exposed as a JSON feed, and you can scrape it by a query structured like, for example, [] (to find a site called "Agrigentum") or [] (to find all sites with the term "bronze"). If you reuse our data, we ask that you credit the GeoDia project and the University of Texas at Austin -- and again, we offer the data without any guarantee, explicit or implicit, of accuracy or correctness. For copyright reasons, we cannot expose full-size images, but we offer the textual data for non-commercial, non-exclusive use.

Technical Specifications

What browsers does GeoDia work on?

GeoDia has been tested and should work properly on Mozilla Firefox 3.6 and above; Google Chrome 5 and above; and Internet Explorer 8 and above. There may be bugs when the site is viewed with some other browsers.

Can I use GeoDia on an iPad or smartphone?

GeoDia does not currently work with touchscreens -- though you will be able to see the site and manipulate the map, you will not be able to slide the timeline. We hope that updates to the various codebases involved will allow us to adapt the site for use on touchscreen devices in the future.

What screen resolution does GeoDia require?

GeoDia works best at a resolution of 1280x1024 or greater.

Using Geodia

How do I find stuff in GeoDia?

When you navigate to the main page, you'll see a frame on the right-hand side of the screen with a series of cultural and regional designations with check-boxes. This frame has four tabs across the top and three down the left side. By default, you begin in the "Browse" tab on the top and the sites tab (represented by a little building) on the side. The other tabs across the top allow you to search for a site by keyword ("Search"); to look at and manage the list of sites produced by browsing or searching ("Results"); and to see the periods and images associated with a site ("Details").

The two other tabs on the side allow you to browse or search images (represented by the icon of a camera) or events (represented by an exclamation point). The Images tab only permits a free-text search, which returns a series of image records with thumbnails. The Events tab acts like the Sites tab, with "Browse", "Search", "Results", and "Details" tabs across the top. In this case, "Results" provides a list of events with brief descriptions, and "Details" provides the full text we have for that event.

If you'd like to browse the sites or events related to a culture or a region, simply check the box/es for the culture/s and/or region/s that you want to browse. If you're only browsing culture OR region, checking more than one box will increase your results set. If you want to browse by BOTH culture AND region, however, checking a new box in one category will limit the results in the other (so you will have fewer results with both "Greek" and "The Aegean" checked than you would if you checked only "Greek"). If you want to check more than three boxes in either category, you will have to manage your results by hand in the "Results" tab, since there will be too many items to display in the timeline, even if you're zoomed out.

When you browse, the number of sites you can see at one time is limited by the height of the timeline. To keep the timeline from being too crowded, we have ranked the sites by importance (in terms of importance to modern scholarship, not in terms of ancient importance). As in Google Earth, when you are zoomed out, you will see only the most important sites. When you zoom in, you will usually see more sites in that area. The timeline ONLY shows sites that are visible on your current map view -- so as you zoom in, new sites will appear and others will disappear. If you're not seeing the site you're looking for in the timeline, check the "Results" section, where you can manage your results list (see below).

If you're looking for something specific, click on the vertical tab for the category (sites, images, events) you're interested in. Then click on the horizontal tab labeled "Search". Enter text into the search box. You can clear previous results by clicking on the X to the right of the term. For sites and events, you can also manage your results using the "Results" tab.

Remember that GeoDia displays only sites, images, and events that are associated with SPECIFIC spatial and temporal information. You won't find general events like the development of agriculture here. Nor will you find images of objects for which we have neither a findspot nor a specific production location.

How do I read the results that I get from a search?

Results for different categories -- sites, images, events -- appear in slightly different ways. The most complex and least intuitive is the "site" category.

When you search or browse for sites, you will see colored markers on the map, and colored bars on the timeline. The map and timeline will match each other exactly: for every site on the map, you will have a bar on the timeline, and vice versa. The colors indicate culture, and when only one culture is involved, they will also match exactly between map and timeline. The bars represent the span of time during which a site was occupied. Bars are broken into segments that represent periods (see above).

In many cases, people from two distinct cultures lived together at a single site (for example, at Greek sites during the period of Roman domination). These situations are represented by zebra-striping for that period in the bar for the site in question. This is an artificial convention, and it doesn't mean that cultures during those periods are "Hellenized", "Romanized", "hybridized", or any other "-ized". It just symbolizes the presence of two different cultures at the same site at the same time, in a way that is recognizable in the material culture from that site. Few sites in the Mediterranean were culturally homogeneous during the entire time they were occupied.

This is the only case in which the map and the timeline will not match exactly. The markers on the map are not zebra-striped. Instead, they take on the color of the new culture that appears at the site. Thus, Roman Athens will be represented by a green-and-red (Greek and Roman) zebra-striped bar in the timeline, but by a red (Roman) marker on the map.

If you click on either a bar in the timeline or a marker on the map, a flag will appear on the map with information about the site and the period, and the "Details" tab will come to the front. It will contain a list of periods for that site, with a collection of images for each period. If you clicked on the map, the list will focus on the period currently in the center of the timeline. If you clicked on a segment of the bar in the timeline, the list will focus on the period represented by that segment. In both cases, the period in focus will be in dark gray in the list. Image results do not appear on the timeline or the map: they only have temporal and spatial values in relation to a particular site. The images here are drawn from the DASe image database of the Liberal Arts Instructional Technology Service of the University of Texas, and are displayed as thumbnails according to fair-use law. To see larger versions, however, you must have a UT EID and log in for access.

Events appear as points on both timeline and map. Like sites, they have spatial attributes; like periods, they are associated with one or two cultures; unlike both, their start and end dates are identical. The color of the markers represents the culture involved (if there are two, the color is associated with the first one listed). If you click on an event in the timeline, a flag with a title and date will open on the map. If you click on an event on the map, the same flag will open, and the timeline will move to center that event. In both cases, the "Details" tab will automatically open.

Events have no associated images and are not connected to sites. The only events included in the database are those that happened in a timeframe no broader than a single year and happened at a specific spatial location. Thus you won't find a marker for "Writing introduced in Greece", but you may find a marker for a geometric pot of 740 BC from Athens that bears the earliest known example of Greek writing.

Why do some cultures have colors, but others are just gray?

Cultures that appear most frequently in textbooks dealing with the ancient Mediterranean world have been given their own colors, so that sites at which these cultures are present can be easily distinguished. There are many other cultures in the ancient Mediterranean, but the ones that appear less frequently in reference books appear simply as gray (there would be too many colors on the map, otherwise). You can determine what culture a gray marker refers to in any given case by clicking on the marker on the map or the bar segment on the timeline. The culture(s) will be listed in the flag that appears above the map marker. You can't browse sites or events for these cultures, but they will appear in searches.

Can I manage which sites are displayed on the timeline?

GeoDia displays sites according to an algorithm that prevents too many sites from appearing in the timeline. In many cases, your search will return more sites than can be displayed. If you want to manage your results manually, you can do so in the "Results" tab. There, you can see a list of all the sites your search returned. To the left of each site name are two icons: an X and a pushpin. The X removes that site permanently from the display. The pushpin centers the map on it. To the right of each site name are two check-boxes marked "show" and "hide". If you wish to always show some sites on the timeline, regardless of the map view, or hide some sites that would otherwise appear, check one or the other box. If no boxes are checked, GeoDia will automatically decide which sites within the current map bounds to display.

Can I manage which events are displayed on the timeline?

Unlike sites, all events within the map bounds are always displayed in the timeline by default. If you would like to remove or hide some events, however, you can do this from the "Results" tab. Events can be removed from the results set by clicking on the X to the left of the list item. They can be hidden by clicking on the "Show/Hide" link in the upper right corner. This link acts as a toggle, so if you decide you want to show a hidden event after all, just click it again to show.

I don't want to find a site or an event, I want to find an image. How do I do that?

You may want to find images of a specific object or building you've seen in a class or in a book. Remember, GeoDia is about context in time and space. If you're associated with UT, you might be able to find a more complete record for a single image in the DASe project. But if you want to see an image of an object in association with the site where it was found, and with other objects of the same time from that site, GeoDia is for you. You can do a free-text search for text in image records in the "Images" tab. You will get a list of all the image records that contain the text you entered into the search field. These records will appear in the search tab itself. For each record, you will see a site name, a thumbnail, and a short caption. You can click on the name of the site to see the image in its chronological context in the "Details" section for that site. The list will jump automatically to the period of the image in question. If you have a UT login, you can click directly on the image for a larger version.

I found some sites. How do I see the images associated with them?

You can call up the images associated with a site from either the map or the timeline. After you have found your site, you can click on the site's marker on the map, and the "Details" tab will automatically open and jump to the period in the center of the timeline at that moment. If you want to see images from a particular period, click on a period in the bar for that site in the timeline, and the image list will automatically center to that period.

How can I view a larger-size image?

You can view an image in full screen mode by logging on using your UT EID and then clicking the thumbnail of the image you would like to view. Unfortunately, if you do not have a UT EID, you can only view the thumbnails.

Can I share a set of results I've put together with someone else?

Yes. For both sites and events, you can provide a link by clicking on the button labeled "Link" at the top of the "Results" tab, and then copying and pasting the text in the field that will appear below.

Can I view my results in Google Earth, or export them as KML?

Yes. For both sites and events, you can export a KML file by clicking on "Google Earth Download" at the top of the "Results" tab. To view your results in Google Earth, just open the file you've downloaded with that program. You will see both locations and a time-slider that reflects the overall timespan of each site in the set, or the date of each event (although neither period information nor images will be available in Google Earth).


I have too many results, and I can't see the things I was looking for. How can I display the sites I want to see?

Most of your searches will return more results than can be comfortably viewed on the timeline. You can find what you're looking for in two ways. First, you can zoom the map in. That will give you more results in the area you're zoomed to, just like Google Maps or Google Earth. Second, you can manually select which sites you would like to appear by going to the "Results" tab and choosing a view option ("Hide" or "Show"). If you leave the setting on "Auto", sites will appear according to GeoDia's algorithm.

I want a certain site always to appear on the timeline. What do I do?

Go to the "Results" tab on the right-hand side of your screen. Look through the list of sites there. When you see the site you'd like to show, click on the "Show" radio button. Now the site will always appear on the timeline, whether or not it is within the bounds of the map on your screen, and it will appear on the map whenever it is within the bounds displayed on your screen. If you click on its bar in the timeline when it is not within the map bounds, the map will jump to it.

How can I see more of the timeline or map?

GeoDia's webpage stretches to fit your current screen resolution. To close the tabs for a little more map space, click on the double arrow on the outside upper left corner of the tab frame.

The map only shows me one or two sites. How do I see more?

As with Google maps, the closer you zoom into an area, the more sites in that area will appear on the map.

The timeline doesn't show any results after my search.

If your search returned positive results (as listed in the results tab), you should see a bar in the timeline that represents the first known culture for that site. If you do not see a bar, try scrolling through the timeline until you see a result.

I found my site, but I don't see any images.

If you can see periods but there are no images attached to them, we probably haven't added any images for that site yet. There are a very large number of sites in the Mediterranean area, and GeoDia is a work in progress. We plan to continue to add information (sites, periods, and images) over time. We also welcome contributions from individuals who are knowledgeable in the field; we are happy to add sites, cultures, or periods and include new images on request. We hope that this will become a tool that will allow researchers, students, and teachers to share information of this type more easily. To see which sites are currently included, and whether they have periods and images, visit our "Overview" page.

I selected a region and a culture. I know there are sites of that culture in what I think is that region, but I don't see them. What's going on?

Since we didn't use standard political divisions to determine the regions, the way we've defined a region may not be the way you define it. To see how our regional divisions work, visit this Google Map.

Specific Examples

I want to find Pompeii, so that I can see where the site is and what sorts of things were found there. How do I do that?

Click on "Search" while you're in the "Sites" tab. Enter "Pompeii" in the search box at the top of the tab and hit the enter key. The search term will appear below the search box, and the results will appear on the map and timeline, and in the results list.

My instructor showed a picture of the Colosseum in class today. I want to see what other buildings and objects date to the same period in Rome. How do I do that?

If you know when the building was built, you might be able to find it by searching for Rome, and then scrolling to the correct period. If not, go to the "Images" tab, type "Colosseum" into the search box, and if an image of the Colosseum is among the results, click on the site name "Rome" for that record. You will jump to the "Details" tab of the "Site" section, and the period list will focus on the period during which the Colosseum was constructed.

I want to know where and when the Battle of Marathon actually happened. How do I do that?

Type "Marathon" into the search box, click on the "events" radio button below the search box, and click on "Search" or hit the enter key.

I'm generally interested in Punic culture. I'd like to see all the Punic sites in the Mediterranean. How do I do that?

Here you might want to use the "Browse" function. In the "Browse" tab at the right-hand side of your screen, check the box for "Punic". You can also go to the search tab, enter "Punic" in the search box, and hit the enter key.

Actually, I'm studying ancient colonization, and I want to see both Punic and Greek sites. How do I do that?

Here you would definitely want to use the "Browse" function. Check the boxes for both "Punic" and "Greek" culture.

I only want to see Punic and Greek sites that are located in the Western Mediterranean.

Use the "Browse" function for this. Check "Punic" and "Greek" under culture, and "Italy/Western Mediterranean" under region. If you don't see sites you thought would be there, look at our region map here. You might need to check the box for "North Africa" as well.

Comments and Feedback

Your information is incorrect for a specific site or image. How can I notify you of the error?

We have set up a blog to provide updates and collect feedback at Please go there and post a comment about any mistakes you notice. We will monitor this blog for comments and try to correct any mistakes that we confirm. If you have a specific published source for the information you believe to be correct, please include it in the comments.

I would like to use GeoDia for teaching or research, but the sites I need aren't included. Can I ask you to add them?

Yes, please feel free to post suggestions for additions on the blog. We will post updates so that you can see what has recently been added, and whether your sites are included. We do not add information on demand, however, so it may be some time before the sites or events you suggested are included.

I have specialized knowledge about the archaeology and chronology of a particular site that is not included, or is not complete, and I would like to add that information to GeoDia. How can I contribute?

Currently, because of the structure of the data and the way they are stored, only a small number of UT participants can add or edit GeoDia entries. If you have expert content knowledge, however, and would like to pass on information or images, please contact Adam Rabinowitz directly at arabinow [at] utexas [dot] edu, and he will get in touch to work out how your information can be added.