Loch Achray

Loch Achray is a small freshwater loch between Loch Katrine and Loch Venachar. The river Achray Water feeds it and the river Black Water drains from it. Ben A'an a popular little mountain is climbed from the car park at the northern edge.
From a road cycling point of view the Duke's Pass road climbs from the western end and although the surface of the road isn't great the climb, views and loop are well worth the jarring.

Shielbrae Road between Cambusbarron and the Carron Reservoir is a challenging single track road located in a lovely landscape but unfortunately the surface is appalling (uneven surface, potholes and loose chips). As an alternative I would recommend using the New Line Road or descend very carefully.