To the west, between Kirk Fell and Pillar, is Black Sail Pass. This is a pedestrian route from Wasdale to Ennerdale, and from there onward via Scarth Gap to Buttermere. A well-graded path now used exclusively for leisure, it was once a thoroughfare for trade between the valleys. The summit of the pass at is crossed by the Ennerdale Fence, a boundary marking the watershed around the head of the valley. Although some sections of the 'fence' are actually stone walls, that running over the top of Kirk Fell is only a remnant, marked by occasional posts.