The Hagia Sophia was built in the remarkably short time of about six years, being completed in 537 ce. Unusual for the period in which it was built, the names of the building’s architects—Anthemius of Tralles and Isidorus of Miletus—are well known, as is their familiarity with mechanics and mathematics. The Hagia Sophia is a component of a UNESCO World Heritage site called the Historic Areas of Istanbul (designated 1985), which includes that city’s other major historic buildings and locations.