Middle Head is one of the seven headlands of Sydney Harbour and looks out through North and South Heads to the Tasman Sea. It lies at the junction between North Harbour, Port Jackson and Middle Harbour. Visitors can walk down to Cobblers Beach or Obelisk Beach, enjoy scenic views of Sydney Harbour from the lookout or take a tour of the historic fortifications and military relics.

This sandstone parapet fort was built in 1801 to ward off a feared French invasion. Inside are a series of interlinking tunnels and passageways that were excavated after the withdrawal of British colonial troops garrisoned in Sydney. The defences continued to be upgraded, and during the Second World War, guns were installed. The guns themselves are now gone but the sandstone pits where they once rested still remain. Another attraction of the fort is the infamous "Tiger Cages" of the Vietnam War-era.