three large cells within the walls. They are entered via thresholds which are 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. Later history Mousa Broch continued to be used over the centuries and is mentioned in two Norse Sagas. Egil's Saga tells of a couple eloping from Norway to Iceland who were shipwrecked and used the broch as a temporary refuge. The Orkneyinga Saga gives an account of a siege of the broch by Earl Harald Maddadsson in 1153 following the abduction of his mother, who was held inside the broch. The site was visited by the antiquarian George Low during his tour of 1774, and he provided the first drawings of the broch. It was visited by Sir Walter Scott in 1814, who described it as "a Pictish fortress, the most entire probably in the world." The geologist and antiquarian Samuel Hibbert visited it in 1818 and provided a detailed account of the site. The first accurate survey was conducted by Sir Henry Dryden in 1852 and 1866. Excavations Mousa was cleared of debris and repaired in 1861 and great quantities of animal bones, especially of otters (which probably inhabited the deserted ruin) were found. Also found were pieces of a clay pot, stone pot lids, a slaty stone about 12 inches long "like a three-cornered file" and a "carved model of a Norway boat in fir" about long. The interior was cleared again by the Office of Works in 1919, and few additional finds emerged. In the National Museum of Scotland in Edinburgh are some pottery sherds, including a large black-burnished rim sherd, probably found during the 19th