The Topkapı Palace (Turkish: Topkapı Sarayı[2] or in Ottoman: طوپقپو سرايى) is a large palace in Istanbul, Turkey, that was the primary residence of the Ottoman sultans for approximately 400 years (1465–1856) of their 624-year reign.[3] As well as a royal residence, the palace was a setting for state occasions and royal entertainments. It is now a museum and as such a major tourist attraction. It also contains important holy relics of the Muslim world, including Muhammed's cloak and sword.[3] The Topkapı Palace is among the monuments contained within the "Historic Areas of Istanbul", which became a UNESCO World Heritage Site in 1985, and is described under UNESCO's criterion iv as "the best example[s] of ensembles of palaces [...] of the Ottoman period."[4]