Broch of Mousa, Scotland

Broch of Mousa (or Mousa Broch) is the finest preserved example of an Iron Age broch or round tower. It is in the small island of Mousa in Shetland, Scotland. It is the tallest broch still standing and amongst the best-preserved prehistoric buildings in Europe. It is thought to have been constructed c. 100 BC, one of more than 500 brochs built in Scotland. The site is managed by Historic Environment Scotland.

Mousa Broch has one of the smallest overall diameters of any broch, as well as one of the thickest wall bases and smallest interiors; this massive construction (as well as its remote location) is likely to be the main explanation for its excellent state of preservation.It stands 13.3 metres high and is accessible via a single entrance at ground level.Once inside, a visitor may ascend an internal staircase to the top.It is the only broch which is complete nearly to the top, including the original intramural stair. It is built of dry stone with no mortar.The entrance is on the west side but has been altered at various times from its original appearance.The entrance passage is 5 metres long and still has an original bar-hole.

Inside a hearth and floor tank can be seen in the central space.There is a low stone bench around the base of the inside wall, which was part of an early alteration to the interior.The broch went through at least two phases of occupation. In its original condition it may or may not have contained a wooden roundhouse resting on the scarcement ledges and presumably on a ring of posts set into the primary floor.At a later date, if the wooden building existed, it was demolished to make way for a small wheelhouse (with three projecting stone piers) in the interior.Scarcement ledges at heights of 2.1 and 3.7 metres might have supported the putative timber building.The other main feature of the ground floor is the three large cells within the walls.They are entered via thresholds which are 0.7 metres above the floor level.Above the lintel of each cell door are further openings which seem designed to let light and air into the chamber behind.The cells all have recesses, or large cupboards, set into the thickness of the wall.

Above the solid base of the broch are six galleries.They are formed by the space between the two concentric walls of the upper part of the broch,and are partly lit by voids.It is possible to walk along most of the galleries.They were probably used by the builders as an aid to constructing the building, rather than for accommodation or storage.

The stair, which begins at the second level, is reached by a doorway in the inner wall face, which has an adjacent cell.There is also an upper cell above the entrance passage.