A type of Iron Age structure found in Cornwall, England, and also in Scotland, Ireland, and Brittany. They are constructed like a gallery, partially or mostly under ground, and are usually covered by a mound of earth and stone slabs. They are generally found near settlements and may have been used as storerooms or as refuges, or both. Many date to the 2nd and 1st centuries BC and the earliest are from Brittany, c mid 1st millennium BC.