In Britain, earthen long barrows predominate across much of the southern and eastern parts of the island.[25] Around 300 earthen long barrows are known from across the eastern side of Britain, from Aberdeenshire in the north down to the South Downs in the south, with two projections westward into Dorset and Galloway.[2] Excavation has suggested that these earthen long barrows were likely constructed between 3800 and 3000 BCE.[2]