Mousa is most famous for its almost perfectly preserved 2,000 year old Iron Age broch (tower).

The island is also well known for its storm petrels. Around 6,000 pairs nest here in the walls of the broch, in the boulder beaches and field walls. Petrels only come ashore at night, and to see and hear them you’ll need to take an evening boat trip. Other breeding birds include arctic terns, black guillemots, arctic and great skuas and a few puffins.

The island has some 400 breeding common seals.