Isle of the Dead is an island, about 1 hectare (2.5 acres) in area, adjacent to Port Arthur, Tasmania, Australia. It is historically significant since it retains an Aboriginal coastal shell midden, one of the first recorded sea-level benchmarks, and one of the few preserved Australian convict-period burial grounds. The Isle of the Dead occupies part of the Port Arthur Historic Site, is part of Australian Convict Sites and is listed as a World Heritage Property because it represents convictism in the era of British colonisation.