Follow the directions on the location info page until you reach the two large distinctive mounds on the left of the road. From here walk along the the track to the second mound where a path leads down to the River Nevis. The path goes over the location used for the castle and the village location is on your left. There is no sign today that filming took place here.
The opening scenes of Braveheart were filmed nearby. Go down to the river and follow the path back towards Fort William for around 100 yards. Go up and over the small mound and the locations are directly in front of you. The location for the barn where the nobles are killed is near the river. To the left of this is the track which the nobles are seen coming down to the barn.