Loch Ness The loch, which lies on the Highland Boundary Fault, is 39km long and up to 230m deep - and might hide a monster!
2. Loch Lomond: The fresh water loch, long celebrated in song, is 36km long and a maximum of 190m deep.
3. Loch Morar: Situated in Lochaber, it covers an area 27sq km and is up to 310m deep.
4. Loch Tay: Located in the Central Highlands is 23km long and has a maximum depth of 150m.
5. Loch Awe: This Argyll and Bute beauty is up to 94m deep
6. Loch Maree: The Wester Ross loch is 20km long.
7. Loch Ericht: Sitting astride the border between Perth and Kinross and the Highlands, the loch has maximum depth of 156m.
8. Loch Lochy: This unimaginatively named waterway, in Lochaber, is 16km long and has an average depth of 70m.
9. Loch Rannoch: Situated below Schiehallion in Perth and Kinross has an average depth of 51m.
10.Loch Shiel: West of Fort William, it is up to 128m deep.