River Lune Weasdale Beck (5.58 km = 3½ mls) at 1.6 miles from the well. Weasdale Beck is the uppermost headwater of River Lune recorded in Environment Agency's Catchment Data Explorer. It then passes the remnants of a Roman fort near Low Borrowbridge at the foot of Borrowdale, and flows through south Cumbria, meeting the Irish Sea at Plover Scar near Lancaster, after a total journey of about . The valley of the Lune has three parts. The northern part between its source and Tebay is called Lunesdale. Below this is the spectacular Lune Gorge through which both the M6 motorway and
Lune of Hippocrates which the arc "AEB" lies. Consequently, the smaller circle has half the area of the larger circle, and therefore the quarter circle AFBOA is equal in area to the semicircle AEBDA. Subtracting the crescent-shaped area AFBDA from the quarter circle gives triangle ABO and subtracting the same crescent from the semicircle gives the lune. Since the triangle and lune are both formed by subtracting equal areas from equal area, they are themselves equal in area. Using a similar proof to the one above, Alhazen showed that two lunes, formed on the two sides of a right triangle, whose outer boundaries