Snapper Island, a close neighbour of Cockatoo Island, is the smallest island in the harbour. Sydney's tiniest island has been radically reshaped by human intervention. It has been flattened and roughly formed into the shape of a ship, with longer sides oriented to the northwest and southeast. Over 1,000 tonnes of rock were blasted from the top of the island and today little evidence remains of its natural form and original vegetation. In the 1930s the island was used as training depot for boys in nautical skills. Two Cabbage Tree palms planted at this time are now a local landmark.