The Dampier Archipelago is a group of 42 islands near the town of Dampier in the Pilbara, Western Australia. The archipelago is also made up of reefs, shoals, channels and straits and is the traditional home of five Aboriginal language groups. It was formed 7000 years ago when rising sea levels flooded what were once coastal plains. The underlying rocks are among the oldest on earth, formed in the Archaean period more than 2400 million years ago. It is named after William Dampier, an English buccaneer and explorer who visited in 1699. Dampier named one of the islands Rosemary Island.