Which loch is Scotland's largest by surface area?

Scotland’s largest loch by surface area is Loch Lomond.

Loch Lomond covers about 71.5 square kilometres and extends roughly 36.4 kilometres from north to south. It lies across the Highland Boundary Fault, the major geological divide commonly associated with Scotland’s Highlands and Lowlands.

The loch was shaped by glaciers during the last ice age. Its northern basin is narrow and deep, reaching about 190 metres, while the southern basin is broader and much shallower. More than 60 islands and islets are scattered across its waters.

Loch Ness is the usual wrong answer because it is Scotland’s largest loch by water volume, not surface area. Loch Lomond is also the largest lake in Great Britain by surface area, although Northern Ireland’s Lough Neagh is larger within the United Kingdom.