Fort Denison was built on an island in Sydney Harbour, Australia, between 1841 and 1857. It was built to defend the harbor. The fort features a Martello tower, a circular tower with several cannons. In the early years of settlement, before a prison was built on shore, the authorities sometimes marooned criminals on the island for long periods of time with only small amounts of rations. The fort’s popular name, Pinchgut, derived from this practice. It now houses a museum, a lighthouse beacon, and a tide gauge.
See also Martello towers .
