Île aux Cochons is the westernmost island of the archipelago, lying some 30 km north-west of Île des Pingouins and 15 km south-west of the Îlots des Apôtres. It is an eroded volcanic dome, scattered with inactive craters, and a coastline consisting partly of low cliffs. Introduced species include cats, rabbits and mice. The introduced pigs that gave the island its name have been eradicated. There is no human infrastructure and visits by researchers are rare.
