Maps of Africa from 16th to 20th century at the Northwestern University Library
The Northwestern University Library has an extensive map collection and they have chosen to digitize and make available a selection of these maps.

The collection includes all of the maps from their "Africana" collection that were not duplicates or in editions pertaining to other subjects (i.e. French maps of Algeria), stated in a link "about this collection". This is a loose collection policy, I suppose. The "about" section goes on to list technical data, such as the resolution and scanning process. They also throw a whole bunch of acronyms about metadata such as MARC, MODS, MIX, and METS, so one would assume there is a fair amount of XML metadata for each image, yet I cannot find it through the site interface.

About the interface: it is fairly well designed, with a search field and a drop down menu to browse the maps by title, date, cartographer, region and publication location. Each map features a click through link which redirects to another site that allows for five levels of zoom, a resolution that gets you absurdly close to the map. Thus the image resolution is great, and definitely usable for remote research. There is also a link to a downloadable TIFF image in the data for every map.

The only metadata associated with each map corresponds with the above search fields, along with size and format data gleaned from a quick right click and "properties". Publication location was an interesting addition and contributes to the provenance of the object--the "about" section also urged questions related to provenance to be e-mailed to the institution. Beyond this there is not much metadata relating to object creation date, authority, etc. Some object descriptions list authority but from reading them it seems it is just the authority listed on the map itself by the cartographer.

All in all this is a nice collection. There could be more metadata, and the separate link for the zoom-able image is not ideal, but the resolution of the image and the history and explanation in the "about" page give a researcher some things to work with. The images failed the "Google image search" test so I'm not sure how accessible this is to anybody who does not already know about it. I imagine the audience for this collection to be researchers already familiar with the Northwestern librarie's collection and wishing to access the maps from another location.