Little Cumbrae is an island in the Firth of Clyde, in North Ayrshire, Scotland. It lies south of Great Cumbrae, its larger neighbour. The underlying geology is igneous with limited outcrops of sedimentary rock. Little Cumbrae House is of 20th century construction, although the island has no permanent inhabitation at present, its population having peakā¦Little Cumbrae is an island in the Firth of Clyde, in North Ayrshire, Scotland. It lies south of Great Cumbrae, its larger neighbour. The underlying geology is igneous with limited outcrops of sedimentary rock. Little Cumbrae House is of 20th century construction, although the island has no permanent inhabitation at present, its population having peaked at 23 in the late 19th century. There is a lighthouse on the western coast.