It was added to the UNESCO World Heritage Site List in 1981.
Traditionally, the Old City has been divided into four uneven quarters, although the current designations were introduced only in the 19th century.
The Old City's monumental defensive walls and city gates were built in the years 1535–1542 by the Turkish sultan Suleiman the Magnificent.
The walls stretch for approximately 4.5 km (2.8 miles), and rise to a height of between 5 and 15 metres (16.4–49 ft), with a thickness of 3 metres (10 feet) at the base of the wall.
Suleiman's wall had six gates, to which a seventh, the New Gate, was added in 1887; several other, older gates, have been walled up over the centuries.
In 1239 he began to rebuild the walls, but they were demolished again by Da'ud, the emir of Kerak.
In 1243, Jerusalem came again under the control of the Christians, and the walls were repaired.