Nybster Broch - reported on BBC News and added site.
Royal Commission Site entry states:
"Nybster Broch was excavated by Sir Francis Tress Barry about 1900, revealing neither guard chamber nor mural cells. It has in internal diameter of 23ft and a wall thickness of 14ft. In 1910 the maximum height of the walls was 5ft 3ins.
The broch is defended by a possibly later forework and the whole is fronted by a ditch about 20ft wide which cuts off the promontory on which the broch stands. To seaward of the broch practically the whole promontory is covered by well-built out-buildings, oblong, circular, and irregular in plan.
Finds include a fragment of 2nd century Samian ware, as well as the more usual bone and stone objects."