Culdee Fell is a Sudrian mountain. It has the reputation of being the highest point on Sodor, with its Summit 2,048 feet above sea level. The Culdee Fell Railway climbs this mountain's southwest side.
In the PC game Railway Adventures, the line is part of the North Western Railway and can be accessed by standard gauge and there is a quarry with a viaduct crossing above. There is also a small lake where Cranky is placed by. Percy was stuck after a landslide collapsed the viaduct and needed to deliver the coal. Thomas, James, Toby, Harold and Cranky helped repaired it.
- Culdee is named after this mountain.
- Translated from Sudric, it means "The Mountain of the Companion of God". This sources from the fact that St. Machan (the patron saint of Sodor, who lived during the sixth century) lived in a cave on the side of the mountain.