The maximum elevation is 28 m, found on the small cliff on the south coast, to the west of which is the only appreciable beach at The Pool.

Geologically, the island is wholly of Old Red Sandstone, from the Devonian period, specifically Rousay Flagstones, dating from about 375 MYA, laid down by a cyclical series of lakes and containing many fish fossils.

About 1000 of the birds are thought to spend the winter months roosting on the island and feeding on nearby South Walls.

[14] Further evidence of pre-historic use is provided by the presence of a 9 m diameter by 0.5 m high turf covered cairn, near The Ool at the southern tip of the island.

[15] Haswell-Smith (2004) maintains there is no written record of any post-Neolithic habitation,[3] and there are 3 further sources that would support that assertion, at least for the past 350 years.

[21] Older texts support the island's use for other livestock however, for instance it is recorded that in 1747–48, 11 oxen were kept on Switha, part of the Burray inventory.