East entrance to the Malinta Tunnel complex on the island of Corregidor. Constructed by the US Army Corps of Engineers between 1922 and 1932, it was used for bomb-proof storage, as a command center, and a 1,000-bed hospital. The main east-west tunnel is 253 m (830 ft) long and 7.3 m (24 ft) wide, with 24 lateral tunnels, each about 49 m (160 ft) long and 4.6 m (15 ft) wide. A double track electric railway ran down the main tunnel. General Douglas MACARTHUR's headquarters and the offices of President Manuel L. QUEZON of the Philippines Commonwealth were located in laterals just inside this entrance.