The Gap, Ocean cliff in Watsons Bay, Australia.

The Gap is a sandstone cliff at the southern entrance to Sydney Harbour, where the rock platform meets the ocean abruptly. The formation runs along the outer tip of the peninsula, with vertical walls dropping straight into the water.

European settlers built a lookout post on the clifftop in the late 18th century to spot approaching ships early. The coastline later became part of Sydney's military defense line during colonial times.

The Gap takes its name from the break in the cliff line where the sandstone meets the Tasman Sea. The headland was home to the Birrabirragal clan of the coastal Darug people before European colonisation. The Dunbar's anchor, recovered more than fifty years after the 1857 wreck, stands on the cliffs at Watsons Bay with a memorial tablet.

A paved walkway leads from the parking area to the viewing platform and is accessible for wheelchair users. The wind can be strong along the open coast, so sturdy footwear and a jacket are recommended.

The only survivor of the Dunbar wreck, sailor James Johnson, clung to a rocky ledge below The Gap for 36 hours before rescue in August 1857. He later worked at the lighthouse near Newcastle and in July 1866 helped rescue a lone survivor of the steamer SS Cawarra. The Dunbar's anchor, recovered more than fifty years later, stands on the cliffs at Watsons Bay with a memorial tablet.