Prehistoric Orkney refers only to the prehistory of the Orkney archipelago of Scotland that begins with human occupation. (The islands’ history before human occupation is part of the geology of Scotland.) Although some records referring to Orkney survive that were written during the Roman invasions of Scotland, “prehistory” in northern Scotland is defined as lasting until the start of Scotland's Early Historic Period (around AD 600). The sites discussed in this article are found on the Orkney Mainland unless otherwise stated.