the Western Channel Pile Light,
which is also known as West Wedding Cake (because of its
shape), is situated at 33° 50ˊ S 151° 15ˊ E, at the western end
of Sow and Pigs Reef, off Georges Head, in Sydney Harbour.

Info on Sow and Pigs Reef at;
http://en.wikipedia.org/wiki/Sow_and_Pigs_Reef