The South Head Signal Station is located on South Head Road, in the eastern suburb of Vaucluse. Captain John Hunter established a 'lookout post' with huts and a flagstaff in 1790, which would serve as a landmark for ships arriving at the heads. Later, a nine metre high brick column and a semaphore mast were built near the flagstaff. A sandstone tower was designed by Mortimer Lewis and built in the 1840s to replace the brick column and in the 1890s was raised to the present four storeys. It ceased as a signal station for Sydney Harbour in 1992 but was taken over by Coast Guard Sydney and has operated since as a Search and Rescue Base, monitoring small craft and recreational boaters.