 One notable feature of the park is the 2,000,000 gallon underground cistern, originally built to hold water for fire-fighting in the event that the fort was attacked and put to the torch.The cistern was drained in the 1950s when the fort was decommissioned, leaving an underground space more than 200 feet in diameter and 14 feet deep.This huge subterranean chamber has an acoustical reverberation time of around 45 seconds, and once attracted the interest of various musicians and recording artists, among them Wayne Horvitz, Pauline Oliveros, and Stuart Dempster.