The tectonic tear assisted the English in subjugating the Highlanders; General Wade's 18th-century military road still runs along the south-east shore of Loch Ness. It was crucial in the defeat of the Highlanders at Culloden Moor, near Inverness, in April 1746. The battle signalled the start of the economic decline of the Highlands. It was accelerated by the Clearances (when landowners evicted crofters to facilitate sheep farming), an exodus to the Lowlands (where the Industrial Revolution was developing the textile industry) and mass emigration.
Thomas Telford, a Scot himself, was appalled at the prospect of further depopulation, and proposed the canal in 1801. The government, aware of the need for a safe short-cut between the east and west coasts of Scotland, accepted, and he set about building the required 23 miles of artificial channels to link the existing three freshwater lochs - from south-west to north-east, Lochy, Oich and Ness - with the open seas.
It is a masterpiece, both in the elaborate flights of locks at Fort Augustus and "Neptune's Staircase", and in the sheer skill involved in carving through tough terrain and ensuring that the water level could be maintained. The project took 21 years, and cost a cool million pounds.