The Nidderdale Caves are a series of caves in Upper Nidderdale in North Yorkshire, England. There are two cave systems and most of the caves are in some way linked with one or the other. The smaller system is the Eglin cave system in the valley of How Stean Beck, a tributary of the River Nidd, associated with How Stean Gorge. The larger system is the Goyden cave system under the valley of the River Nidd, which flows east from Scar House Reservoir, then south, and shortly after disappears underground down several sink holes to reappear at the rising just beyond the village of Lofthouse. Cavers are able to access several sections of this system via the different entrances.
The caves are a Site of Special Scientific Interest designated in 1987 under the name Upper Nidderdale.
From north to south:
Entrances in bold are classed as distinct caves in their own right and entrances not in bold are alternative entrances into those caves.
Explored passages total 8.3 km.
At present cavers and cave divers have explored and linked together the caves from Manchester Hole through to New Goyden pot. The section from Goyden to New Goyden is only traversable with diving gear although cave diggers have opened up a way from New Goyden to Frog pot and have attempted to find and open up a link from Frog pot to Goyden pot.
Cave divers have attempted to explore the link between New Goyden pot and Nidd Head. At New Goyden pot they have explored eight flooded passages (sumps) with various lengths of dry passages between. At the Nidd Head rising they have dived for over 850 metres with still about 1 km gap left to explore between the two caves.
Water from the moors above Angram and Scar House drains into the reservoirs, which in turn feed the River Nidd. Below Scar House dam the Nidd flows east then turns south, and shortly after disappears underground through a series of small fissures in the exposed limestone inlier. All the water from the various fissures enters the large stream passage of Manchester Hole. The underground stream can be followed along an impressive 3 to 4 sq m passage to the equally impressive massive blockfall cavern of the Main Chamber. Faulting here is not only responsible for the blocks but has allowed incursions of more than one stream to aid the process of block fall. At present one small stream enters at the southern end, but previous flooding such as in 1998 has opened up choked passages, allowing a large volume of water to enter Main Chamber. A huge section of the mud bank in that chamber collapsed and the flood subsiding refilled the passage. This process of opening and closing of inlets has probably been repeated many times over the centuries. The stream at the base of the chamber flows amongst fallen blocks to enter a passage of fine proportions, but the roof soon dips to where the stream enters a low area known as ‘the grovel’. The roof quickly rises again in Fossil Passage, where a narrow but high passage can be followed round more than one bend to a wider section. Here a small tube high up on the left leads to a permanently flooded section (static sump) 46m long that connects with Goyden Pot cave at Pillar Pot. The stream flowing through Manchester Hole does not connect with this static sump but instead flows onwards for a few metres to the ‘duck’. At the duck the stream make a sharp right turn almost flowing back on itself through a hands and knees crawl with limited airspace. After a few metres of the ‘duck’ the passage once again enlarges and the stream then flows on for a few more metres to enter downstream sump 1. This sump is 15m long and enters Divers Chamber. The stream flows out of the chamber along a short passage to enter sump 2, a small constricted passage that enters the Lesser Stream area of Goyden Pot.