The Caledonian Canal runs for 60 miles along the Great Glen from Corpach near Fort William in the South West to Inverness in the North East.

The canal was started in 1803 to plans produced by Thomas Telford following survey work by James Watt thirty years earlier. It was the biggest of the building schemes undertaken by the Government to provide work and stem the flood of emigration from the Highlands. The huge scale of the work and the shortage of skilled engineers meant that the seven year schedule and £350,000 budget always looked optimistic. It was: by the time the canal finally opened in 1822 it had taken 17 years and cost £840,000. And instead of the 20 ft. depth in Telford's plans, the canal when it initially opened was only 14 ft. deep, too shallow for many of the increasingly large ships being built at the time.

Neptune's Staircase is a staircase lock comprising eight locks on the Caledonian Canal. It is the longest staircase lock in the United Kingdom, and lifts boats 64 ft. (19.5 metres). The locks were originally hand-powered, but have been converted to hydraulic operation. The base plinths of the original capstans are still present, although the capstans themselves are now gone.

The current lock gates weigh 22 tons each, and require a team of three lock-keepers (at minimum) to run the staircase.

Photo: aeroid, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons