Just beyond the East Pool you pass through the wall for a view of the West Pool, another favourite haunt of seals. This is also an Arctic Tern colony and you should keep to the designated path. Known in Shetland as the ‘Tirrick’ the entire colony will defend their territory by swooping from a great height to frighten any intruder. From here follow the trail past the west shore of the small loch to its north-west corner. This loch is a favourite bathing pool for birds and has been known to accommodate the Red-throated Diver.
Mousa has been populated from earliest times through until mid 19th Century. At the north end of the loch there are Brunt Mounds dating from the Bronze Age (c1500BC). The ruins north of the loch are the abandoned croft houses and the ruin on the hill to south-west was the house of a Lerwick merchant. The stream from the loch once powered a Norse mill, the ruins of which can also be seen.
From the loch follow the trail to the broch. Mousa Broch is the best preserved example of an Iron Age (c300BC to 200AD) broch having its walls and internal galleries complete for the most part, although any wooden internal structures or roof has disappeared. Mousa broch is open to the public and can be explored with care. Brochs appear to have been defensive although their precise function is the matter of heated debate among archaeologists and historians.
From the broch follow the coast back to the start point at West Ham. Use the boardwalks where applicable and avoid walking on the shingle beach at Burgi Ayre.