The route and the seclusion of the dale make it popular with walkers and lovers of The Dales. National Cycle route 68 (also known as the Pennine Cycleway) that runs from Derbyshire to Berwick-upon-Tweed passes through the dale. The C5101 road runs through the dale from the nearest main road at Sedbergh (the A683 and A684) to Newby Head Moss, east of the dale head, where it meets the B6255 Hawes to Ingleton road. Western Dales Bus operate a year round Saturday and summer Sunday service between Dent station and Sedbergh with stops en route. The Dent Fault cuts across the valley close to the village of Gawthrop, marking a geological boundary between the Carboniferous Limestone of Deepdale and the Craven Dales to the south and the older Silurian and Ordovician rocks of the Howgill Fells to the north. The Upper Dentdale Cave System, which is east of Dent, was recognized as a site of Special Scientific Interest (SSSI) in 1998. The cave system extends for beneath the valley floor under the River Dee and is notable for providing a unique insight into how caves are formed in valley floors. Dent Marble was quarried and polished in Dentdale between 1760 and 1909. Both the viaducts that carry the Settle-Carlisle line over the dale are constructed from Dent Marble. The opening of the railway afforded the opportunity to export the marble out of the dale for the first time. The stone is not actually marble, it is a highly polished form of Black Limestone.