Glenfinnan Viaduct is a railway viaduct on the West Highland Line in Glenfinnan, Inverness-shire, Scotland. Located at the top of Loch Shiel in the West Highlands of Scotland, the viaduct overlooks the Glenfinnan Monument and the waters of Loch Shiel. The viaduct is built from mass concrete, and has 21 semicircular spans of 50 feet It is the longest concrete railway bridge in Scotland at 416 yards (380 m), and crosses the River Finnan at a height of 100 feet.