GEOnet World Place Names Server - A database of World place names developed from the country gazetteers that were once published by the Defense Mapping Agency (now the National Imagery and Mapping Agency) and its predecessors. It contains place names for over 5 million features throughout the World.
Shtetl Seeker - Shtetl Seeker is a searchable database that provides information on the location of populated places in Eastern Europe, many of which no longer exist.
Undersea Feature Names - Gazetteer of Geographic Names of Undersea Features from the British Oceanographic Data Center.
Getty Thesaurus of Geographic Names - The Getty Thesaurus provides information on place names related to art, architecture, art history and related subjects, such as history and archaeology.