The Basilica Cistern is the largest of several hundred ancient cisterns that lie beneath the city of Istanbul; built in the 6th century A.D., it acquired its name from a great basilica that used to stand over the location. The cathedral-size cistern is an underground chamber approximately 138 m (453 ft) by 65 m (213 ft) capable of holding 80,000 cu m (2,800,000 cu ft) of water. The ceiling is supported by a forest of 336 marble columns, each 9 m (30 ft) high, arranged in 12 rows of 28 columns each spaced 5 m (16 ft) apart. The majority of the columns in the cistern appear to have been recycled from the ruins of older buildings from throughout the Byzantine Empire. They are carved and engraved out of various types of marble and granite.