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 Information Institutes Vocabulary Program (VP)." Each entry contains latitude and longitude, place names and types, and sources of information (usually standard reference sources). Names are arranged in an hierarchical structure of world places. One of the most powerful features of the database is the availability of variant and historical names for places.