The flying car sequence in Harry Potter and the Chamber of Secrets was filmed at Glenfinnan Railway Viaduct 20 or so miles west of Fort William. The viaduct carries the Fort William to Mallaig railway across the Glenfinnan valley.
In the years up to 1901, Sir Robert McAlpine took on a huge civil engineering challenge with the building of the West Highland Extension Railway from Fort William west to Mallaig, though that was not the originally intended destination. One of the largest structures on the railway is the Glenfinnan Viaduct. This is 416 yards long and made up of 21 arches, the tallest of which is 100ft high.
What is less obvious from a distance is that the viaduct is also curved, leading the track round the head of the River Finnan valley. The viaduct is made of concrete, something else not often appreciated. When the railway opened the official handbook noted: "Many authorities on matters of taste, declared when this viaduct was first proposed, that it would prove a monstrosity, sufficient in ugliness to take away all the charm and beauty of the scene. Few would endorse this opinion now." Indeed, though perhaps with fewer commas.
Glenfinnan Station is a little to the west of the viaduct, approached by trains through a deep cutting. A number of stations on this line have lost their original station buildings. Glenfinnan hasn't, largely because of the efforts of enthusiasts who have converted the buildings into a railway museum. And across the station car park are two disused railway carriages. One is now a camping coach, the other is the Glenfinnan Dining Car, complete with a terrace on its southern side overlooking the trees in the valley below. The camping coach carries on a tradition that at Glenfinnan dates back to the 1930s, and which used to be common at many stations on this line.