This is not strictly an earthworks, more a souterrain. Earth houses were not houses for living in, and do not seem to have had a defensive purpose as they are obvious from the ground. They may have been more a type of cellar. These were usually built next to a hut in a small group of dwellings, and this one dates from around 0BC. Just inside the passage on the left side there is a cup-marked stone the builders presumably swiped from a stone circle. (See next picture)