The Medieval Crusader City of Rhodes was declared a World Heritage site by UNESCO in 1988. The Order of St John of Jerusalem occupied the city from 1309 to 1523. Later it came under Turkish and Italian rule. In the fortified city one can still see the Palace of the Grand Masters of the Order of St. John, as well as the Crusader hospital and the Street of the Knights. Next to them are remnants of earlier and later periods, such as a HellenisticTemple to Aphrodite, dating from the 3rd century BC, and the Ottoman Mosque of Sultan Mustafa, built in 1765.