The US Geological Surveys online Geographic Names Information System contains data on nearly 2 million physical and cultural geographic features in the US. Facts include federally recognized feature name, feature type, elevation, estimated 1994 population of incorporated cities and towns, state and county in which the feature is located, latitude and longitude of the feature location, and more....

The Getty Information Institute offers this massive browsable and searchable "structured vocabulary" of almost one million place names and 900,000 places around the world. Information in the thesaurus is derived from such Getty projects as "the Bibliography of the History of Art (BHA), the Foundation for Documents of Architecture (FDA), the Getty Center Photo Study Collection (GCPS), and the Getty...