Clapdale is a small dale lying to the north of Clapham Village and below the southern slopes of Ingleborough.

The head of Clapdale is Trow Gill, a ‘dry', limestone ravine.
Prior to the melting of the glaciers at the end of the last ice age, Trow Gill was a route for rainwater draining off the southern slopes of Simon Fell. Following the end of the ice age, the water from Simon Fell found a new route and now disappears down Gaping Gill Pothole and reappears as Clapham Beck at Beck Head Cave, close to Ingleborough Cave. From Beck Head Cave, Clapham Beck flows southwards through a valley with the impressive Thwaite Scars along the eastern side before flowing through a heavily wooded area into an ornamental lake created in the 19th century. This part of the dale forms the Ingleborough Nature Trail.
After exiting the lake, Clapham Beck flows through the village of Clapham and then turns westward to flow into the Irish Sea at Lancaster via the River Wenning and the River Lune.