Ardnamurchan is a beautiful place, wild and unspoilt (as beautiful as the Isle of Skye in my opinion), and a great idea for a day trip from Fort William is to drive to Ardnamurchan Point, the most westerly point on the UK mainland. The drive there (50 or so miles from the Corran ferry to Ardnamurchan Point) provides you with some breathtaking scenery and arriving at the lighthouse you have fantastic views out to sea and the islands. You can visit the lighthouse itself and there is a cafe where you can have light refreshments.
You can combine a trip to Ardnamurchan Point with a “round robin” trip around the Ardnamurchan Peninsula which is one of the most unspoilt areas of the West Highlands.
A great place to stop for lunch or dinner is the Glenuig Inn, an eco-friendly Inn about 35 miles from Fort William which serves delicious home-cooked food all day.