Largest underground train depot (metro, public transit)

Singapore’s Kim Chuan Depot, measured at 800 m (2,624 ft 8 in) in length, 160 m (524 ft 11 in) in width and 23 m (75 ft 5 in) in height, has a total volume of 2,994,000 m³ (1,057,321,122 ft³), making it the world’s largest underground depot (metro, public transit). Opened in 2009, the depot took five years and $295 million Singapore dollars (£131 million; $209 million) to construct. It houses equipment, stabling and maintenance facilities for up to 70 three-car driverless trains, which operate on the Circle MRT Line and future Eastern Region Line.