When you leave Belleek, do not take yet take the A46 eastwards for Enniskillen - but choose the B52 going south instead. Drive southwards for a few miles and at the major crossing coming up take the second left towards Lough Navar Forest and Derrygonnelly. This crossing can be confusing, take it easy and your time.
You are now entering quite hilly country and will after a while see signposts for Lough Navar Forest, a nature reserve. Once you spot the small car park on the left turn in here and study the map displayed here.
You are about to take the Lough Navar Forest Drive, one of the hidden gems of Fermanagh. Enjoy - but always remember that most of the drive is on a single-track, one-way road. Never, ever, attempt to turn around and go back for the view you just missed. Rather drive slow and observant.
Make sure to follow the signs for the viewing point at a three-way crossing deep in the woods and you are in for a breathtaking treat - standing on top of the Cliffs of Magho you will enjoy a bird's eye view of Lower Lough Erne. Take in some fresh air here, then make your way along the road to the park exit.
At the exit you turn left, pass the entrance again and make your way down to the A46, there are splendid castles waiting ...