of the Great Glen Fault, and is the only sea loch along the fault. About 35 km long, it opens onto the Firth of Lorne at its southwestern end. The part of the loch upstream of Corran is 15 km long and an average of about 2 km wide. The southern part of the loch is wider, and its branch southeast of the island of Lismore is known as the Lynn of Lorne.

Loch Eil feeds into