Fort Philip, Sydney

Fort Philip
Observatory Hill, Sydney, New South Wales in Australia
Remains of Fort Philip today
Fort Philip Location of Fort Philip in Greater Sydney
Coordinates	33°51′34″S 151°12′17″E / 33.8595°S 151.2048°E / -33.8595; 151.2048Coordinates: 33°51′34″S 151°12′17″E / 33.8595°S 151.2048°E / -33.8595; 151.2048
Type	Former fort
Site history
In use	1803 (1803) – 1840 (1840)s
Fate	Partially demolished and repurposed as the Sydney Observatory from 1858 (1858).

Fort Philip was a citadel style fort constructed as part of the first defensive works of the penal settlement of Sydney, located on Observatory Hill in the Sydney suburb of Millers Point, New South Wales, Australia. The fort has been demolished and the local government heritage-listed site repurposed as the Sydney Observatory.

Governor John Hunter ordered a fort to be built and Fort Phillip was commissioned in 1804 by the third New South Wales Governor (in office 1800–1806), Philip Gidley King, partly as a response to external threats such as a possible French attack in 1803 and partly due to the internal unrest from rebellious convicts reflected in Australia's only major convict rebellion at Castle Hill in March 1804. This was dubbed the Battle of Vinegar Hill as most of the convict rebels were Irish. Windmill Hill (later Observatory Hill) was chosen as a fort location as it was the highest point above the colony, affording commanding views of the Harbour approaches from east and west, the river and road to Parramatta, surrounding country and of the entire town below. The fort was never fully completed and never fired a single shot in anger.

A flagstaff was built in 1825 on the eastern wall of the fort, which sent messages to ships in the harbour and the signal station at Fort Denison and South Head.