There are three Scheduled Ancient Monuments in the borough, a Bronze Age cairn in Stalybridge, Buckton Castle, and Nico Ditch. Buckton Castle is a 12th-century enclosure castle near Carrbrook and was probably built by one of the earls of Chester. The castle lay ruinous by 1360, and has been described as "one of England's most important castles". Nico Ditch is an earthwork running from Ashton-under-Lyne in the east to Stretford in the west, in the borough of Trafford. It survives to a depth of in some places and is up to wide.