The Sanctuary of Truth (Thai: ปราสาทสัจธรรม) is an unfinished museum in Pattaya, Thailand designed by Thai businessman Lek Viriyaphan. The museum structure is a hybrid of a temple and a castle that is themed on the Ayutthaya Kingdom and of Buddhist and Hindu beliefs. The building is notably constructed entirely out of wood, specifically Mai Deang, Mai Takien, Mai Panchaat, and Teak. It contains only wood-carved idols and sculptures. Construction first began in 1981 and is still in construction, though visitors are permitted inside with hard hats. Located on 13 hectares of land, the temple houses an internal space of 2,115 m², with the tallest spire reaching to 30 m.