Hull Pot Beck rises on the western side of Plover Hill and flows into Hull Pot, which is the largest natural hole in England. Hull Pot measures long by wide and deep. The water then flows under Horton Moor before re-appearing just east of Horton in Ribblesdale as Brants Ghyll Beck, where it flows into the River Ribble. Local legend has it that the waters from Hull Pot and Hunt Pot cross each other underground without mixing. This is said to have first been noted when a sheep wash was undertaken in one stream thereby making it muddy, and the husks of oats being dropped into the other stream and both having exited into the Ribble without mixing together.