The Ochil Hills dominate the northern third of the county, where Ben Cleuch, Clackmannanshire's highest point, can be found. The northernmost part of the county lies in the Upper Glendevon Reservoir. Strathdevon is immediately to the south of the steep escarpment formed by the Ochil Fault, along which the Hillfoots Villages are located. Strathdevon mostly comprises a lowland plain a few hundred metres either side of the River Devon, which joins the Forth near Cambus. There is also the Black Devon river that flows past the town of Clackmannan to join the Forth near Alloa. This confluence once had a small pier, for portage to Dunmore pier on the south shore, and anchorage of smaller sailing ships, while others of greater tonnage could be accepted at Dunmore pier on the opposite banks of the Forth. Roughly in the centre of the county lies the Gartmorn Dam County Park, and there are small patches of forest in the south-east of the county. Two unnamed peninsulas are formed by meanders in the river Forth along Clackmannanshire's southern boundary; the easternmost of these has two small islands - Tullibody Inch and Alloa Inch - either side of it.