Completed in 1932 after 10 years of construction, the Malinta Tunnel complex is built into the side of a hill and was used by the Americans as a bombproof bunker, for ammunition storage, and also as a hospital. The tunnel spans 250m, with numerous laterals branching off, one of which was used as General MacArthur's HQ.
At times there is a sound-and-light show, in case you need audio and visual cues to imagine the drama here in 1941–42. Some areas still have typewriters and other furnishings sitting untouched from that time.