The town is situated on the River Forth at the foot of Craigmore ( high). Since 1885, when the Duke of Montrose constructed a road over the eastern shoulder of Craigmore to join the older road at the entrance of the Trossachs pass, Aberfoyle has become the alternative route to the Trossachs and Loch Katrine; this road, known as the Duke's Road or Duke's Pass, was opened to the public in 1931 when the Forestry Commission acquired the land.