 A party including Bull and Borchgrevink briefly landed there, and claimed to be the first men to set foot on the Antarctic continent—although the American sealer John Davis believed he had landed on the Antarctic Peninsula in 1821.Bull's party also visited Possession Island in the Ross Sea, leaving a message in a tin box as proof of their journey.Borchgrevink was convinced that the Cape Adare location, with its huge penguin rookery providing a ready supply of fresh food and blubber, could serve as a base at which a future expedition could overwinter and subsequently explore the Antarctic interior.