Fort Philip, Military fort in Millers Point, Australia

Fort Phillip was a citadel-style fort begun in 1804 on Observatory Hill, then called Windmill Hill, the highest point above Sydney. It was never completed and never fired a shot; only the eastern rampart survives, and the Sydney Observatory was built on the site in 1858.

Governor John Hunter commissioned the fort in 1804 to defend against French threats and suppress potential convict rebellions within the colony. The site later transitioned to scientific use when the Sydney Observatory was established, marking the end of its military function.

The site represents a shift from military defense to scientific inquiry, marking how the colonial settlement transformed its relationship with land and knowledge. This transition reflected the growing importance of astronomy in navigation and timekeeping for ships in the harbor.

The site is best reached on foot and sits near other heritage buildings on Observatory Hill, making it easy to combine visits to several locations in one walk. Access is available year-round, though weather conditions may affect visibility and the condition of the exposed remains.

The 1847 signal station replaced the fort's 1825 flagstaff and was designed by colonial architect Mortimer Lewis. It relayed messages to ships in the harbour and to the signal stations at Fort Denison and South Head. The fort itself never fired a shot in anger and was never fully completed.