Stored in our "location" content type

This is where the coordinates are created and maintained. See, for example, location 562375978. Along with the basic coordinates themselves, locations store temporal attestations (for archaeologically and historically attested periods of activity) and references to secondary literature. At present, secondary references are bare text fields, but plans call for their elaboration into complex content in their own right (see Milestone Bibliographic Basics). Locations are also scheduled for enhancements to explicitly report spatial metadata regarding their precision, accuracy, origin(s) and system of reference (see Milestone Geo Precision).

Mapped in our "place" content type

Pleiades places bring together locations with names and other information to fully describe ancient sites, regions and so forth. The view for each locateable place includes one of our OpenLayers maps, pinpointing the place in question. Consider, for example, place 638856, known in antiquity as Hephaistion (mod. Yanar Taş). This, by the way, is the place that brings together location 562375978 (see above) with the attested name Hephaistion.

We also use OpenLayers maps with our browse folders. Plone calls these structures "Smart Folders". They are essentially the results of criteria-based queries across all the content in our database, dressed up to look like regular Plone folders. Consider, for example, our smart folder of temples, sanctuaries, shrines, monuments and tombs. These places aren't contained in that folder; rather, they're classified according to that "place type" and pulled together on demand for display. Clicking on the smart folder's map tab produces a map view, displaying the locations of the places pulled together by the smart folder.

Syndication-ready in our web feeds

Web feeds are in increasingly wide use for a number of purposes. Various pieces of software, called feed readers, make use of the web feeds provided by some web sites to alert their users to updates. Feeds are widely used on news sites and blogs, for example. Feeds also provide a way for web sites to provide other web applications with descriptive links to their content, thereby facilitating a range of on-the-fly, cross-site linking and interactions, as well as "syndication" or reuse of content.

Our places and our smart folders all provide web feeds using the Atom Syndication Format (a flavor of XML designed for this purpose). These feeds are enhanced, according to a standard mechanism called GeoRSS, with our coordinate data. This combination ensures that all Atom-capable feed readers can make immediate use of our feeds. GeoRSS-aware feed readers (and other processes) can go a step further, mapping these links and summaries of our content, or even performing spatial queries against them (for example, to provide a "Pleiades content nearby" link on another website).

If you'd like to see what our Atom+GeoRSS feeds look like, consider either of the following examples. Despite being XML, these feeds are human-readable. Depending on how your web browser is configured, you may need to save the feed to a file and open it with a text editor, or employ the "view source" in your browser. Firefox 2, for example, applies a standard style to "raw" feeds like ours, rendering a subset of the content for each entry in a standard way and offering to help me "subscribe" to the feed using a web-based or locally installed feed reader.

• http://pleiades.stoa.org/places/638994.atom is an example of a feed for one of our places
• http://pleiades.stoa.org/places/temple.atom is an example of a feed from one of our smart folders

Google Earth Ready

Google Earth is probably the most hyped of several virtual globe programs now available. In the company's own words it combines the power of Google Search with satellite imagery, maps, terrain and 3D buildings to put the world's geographic information at your fingertips. Google Earth reads (and can map the content of) its own XML language, called KML. Just as we produce Atom+GeoRSS summaries of our content, we also produce KML summaries. This capability underlies the "view in Google Earth" links that accompany all our OpenLayers maps. Moreover, by taking certain configuration steps with the website, we also alert the Googlebot to the location of our KML. Consequently, Google Earth users can now find our data through spatial + keyword searches in Google Earth without knowing that Pleiades even exists. Clicking on a point symbol in Google Earth displays a pop-up with summary information and an appropriate link back to our site.

If you are unfamiliar with the topography or archaeological remains of southern Turkey, you should spend some time browsing with our data in Google Earth. Sean's been going crazy about it. Be advised that, at maximum zoom, the center of a Pleiades place mark may fall up to 2km from the actual site (though, in practice, many are much closer). This is a consequence of the difference in scales between the Barrington Atlas source map (1:500,000) and the high resolution imagery Google purchases for display in GE, boasting pixel resolutions of 15m or better. Try one of the following examples:

• http://pleiades.stoa.org/places/638994.kml is an example of KML for one of our places
• http://pleiades.stoa.org/places/temple.kml is an example of KML from one of our smart folders

For a peek at even more interesting possibilities, make sure you enable the Geographic Web layer in Google Earth.