In which country is the Glenfinnan Viaduct?

with "glen" in the name Scotland was the obvious choice.

Just take the trip from Fort William to Mallaig on the train you’ll recognize as the Hogwarts’ Express.

BlueEyedAlien, it's one of two. The other is the North Yorkshire Rail from Pickering to Whitbey. There's a tiny town along the route that stood in for Hogsmeade station, with the walkway over the track. Visited there and rode the train. Very cool.

thought that was in the Potter films