Speedwell Cavern in Castleton is experienced through a fascinating boat ride across the flooded workings of an 18th Century lead mine where visitors enter the inner world of the underground cave system in the heart of the Peak District National Park. Set at the foot of the spectacular Winnats Pass, high above the village of Castleton, Speedwell Cavern takes you on an incredible underground boat journey. Descend the 105 steps from the almost hidden cave entrance to the landing stage of an underground canal where you step on to your tour guides’ boat. Typically, boat trips are taken to experience the cavern which are fully supervised by experienced guides. Visitors are taken deep inside a limestone hill to the ‘bottomless pit’, a huge underground lake in the natural Speedwell Cavern.