The WikiLocation API is for developers wishing to search for Wikipedia articles by location. The data is gathered by downloading the Wikipedia database on a weekly basis and then parsing all of the geocoded entries. This data is stored in a database where it is able to be accessed via the API.
WikiLocation supports 36 languages, totaling over 3.8 million articles. At present, there are over 1 million entries from en.wikipedia.org alone.
In addition to searching via location, users can also search via the venue and spot IDs of the two most popular geo-location networks; Foursquare and Gowalla as well as by Yahoo! WOEID. The API uses RESTful protocol and responses are formatted in XML, JSON, or JSONP.
The Wikilocation API has expanded to include 36 languages. The geo API for Wikipedia allows developers to find articles with subjects near a specific location. With the new languages, there are now over 3.8 million geocoded articles available via this unofficial API from developer Ben Dodson.
There are any number of questions that can be answered by Wikipedia, but you can add "where am I?" to the list. Given any latitude/longitude coordinates, the WikiLocation API will find you corresponding Wikipedia articles to tell you about your surroundings.