Description: St. Cuthbert's Leadworks operated by the Bishop of Bath and Wells lies at the southern end of the valley. In 1860, the owners of Wookey Hole Paper Mill, concerned about pollution of their water supply, traced the water from St. Cuthbert's Swallet to Wookey Hole using 'Vanadium Red' dye. This provided the basis for a successful lawsuit in 1863 against the St. Cuthbert's Leadworks for polluting the stream.