Once described as 'a fleet of Dreadnoughts in line astern', the Treshnish Isles are a group of uninhabited islands, islets and rocky outliers in the Inner Hebrides, lying to the west of the island of Mull. Composed of basalt lava, they include the distinctively shaped Bac Mor or Dutchman's Cap, Lunga (the largest in the group), Fladda, Bac Beag, Sgeir an Eirionnaich, Sgeir na h-Iolaire, Sgeir an Fheoir, Cairn na Burgh More, Cairn na Burgh Beg and Sgeir a' Chaisteil.
Purchased in 1938 by explorer and naturalist Niall Rankin (1904-65), the islands were sold to the Hebridean Trust in 2000.