A well-preserved and easily accessible Iron-Age broch, Carn Liath is located on a raised beach on the Sutherland coast, next to the A9 road, 1¼ miles (2 km) east of Dunrobin Castle and 3 miles (5 km) southwest of Brora. It was built around the end of the first millennium BC or into the first century AD, with surrounding houses which may have been occupied as late as 400 AD. Externally, the broch appears as a low circular wall at the top of a knoll, which has been artificially steepened. However, internally walls in excess of 3.6m (12 feet) remain, containing steps and passages. The entrance faces east and comprises a well-preserved lintelled-doorway, once fitted with a wooden door, and a stone-walled passage leading in from the outer wall which includes a guard-cell. In the floor of the broch are three sunken chambers which were perhaps for storage.
The purpose of such brochs is thought to have been defensive, most-likely providing protection to the community living in the nearby houses in times of threat.
Carn Liath was excavated on the instructions of the Duke of Sutherland in the late 19th C. and the artefacts discovered are held in Dunrobin Castle.
