This exceptional Neolithic cairn was erected, using basic tools and without mortar, around 2700 BC. (Stonehenge dates from 2800 to 1560 BC). Its design is so clever and building work so skilful that it is believed by some to be the tomb of the head of a clan or reigning family. It is surrounded by a moat and fully covered by an 8m-high and 35m-diameter mound (Maes Howe means big mound).