The Grey Cairns of Camster are two large Neolithicchambered cairns located about 8.5 miles (13.7 km) south of Watten and 5 miles (8.0 km) north of Lybster in Caithness, in the Highland region of Scotland. They are among the oldest buildings in Scotland, dating to about 5,000 years ago. The cairns demonstrate the complexity of Neolithic architecture, with central burial chambers accessed through narrow passages from the outside. They were excavated and restored by Historic Scotland in the late 20th century