The viaduct describes a huge arc across the glen, well inland of the Monument but still within sight of the loch.
The viaduct was built as part of the West Highland Railway project to between Fort William and Mallaig, a route that today is known as the Road to the Isles. The section to Mallaig was officially known as the West Highland Extension Railway.
The engineers were Robert MacAlpine and Sons, who built to a design by architects Simpson and Wilson. MacAlpine decided to build the viaduct from concrete, as a cheaper alternative to stone or steel. The viaduct curves 240 metres and reaches 30 metres above the streambed below it.
The arches are on a 15-metre span (50 feet). The design is completely utilitarian; there is no decoration or ornamentation at all; a rarity among Victorian engineering projects!
A tradition says that a horse and cart fell into one of the hollow piers and were buried when concrete was poured into the space. This is apparently untrue, though may indeed be true of the Loch nan Uamh Viaduct further west.
It seems quite likely that the great curve of the viaduct was placed to give the best possible view to the striking Glenfinnan Monument on the loch shore.
There is a viewing area for the viaduct off a path behind Glenfinnan station museum, but perhaps even better are the viewing area for the Monument itself, behind the visitor centre, or indeed, the top of the Monument itself gives excellent views up the glen to the viaduct.
For the ultimate experience, though, you can take the Jacobite Steam Train from Fort William to Mallaig. The train makes daily trips during the summer months.
Our Verdict:
The viaduct is in a quite exceptional setting, just up the glen from the head of Loch Shiel. It truly is one of the most beautiful locations in all of the Highlands.