The geology of the island is columnar basalt, similar to that of neighbouring Staffa.

It is part of the Loch Na Keal National Scenic Area, one of 40 in Scotland.

In the early 20th century the island was farmed by John MacColum, known as "Johnny Colonsay", but he and his family were forced out by a plague of rats.

[1] The island is owned by the family of Viscount Blakenham but has not been permanently inhabited since the 1940s.

[6] The 2nd Viscount's daughter, Cressida Cowell, the author of children's books including How to Train Your Dragon, spent childhood summers on the island and cites the Inner Hebrides as an inspiration for her books, suggesting they are "one of the most beautiful places on Earth" and "the kind of place where you expect to see dragons overhead".