Nidderdale Caves facts for kids
The Nidderdale Caves are a fascinating network of underground passages located in Upper Nidderdale in North Yorkshire, England. This area is famous for its beautiful countryside and hidden natural wonders. There are two main cave systems here: the smaller Eglin cave system, found near How Stean Beck and How Stean Gorge, and the much larger Goyden cave system. The Goyden system is special because the River Nidd actually disappears underground into several sinkholes and then reappears further south near the village of Lofthouse. This makes exploring these caves a unique adventure for cavers!
The Nidderdale Caves are so important that they are protected as a Site of Special Scientific Interest (SSSI) since 1987. This means they are recognized for their special natural features, like their geology and the way water flows through them.
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Exploring the Cave Entrances
The Goyden cave system has many different ways to get inside, known as entrances or "pots." Some are main caves, while others are alternative routes into the same system. Here are some of the key entrances, listed from north to south:
- Manchester Hole (Length 578m)
- Bax Pot (an alternative way into Manchester Hole)
- Lesser Stream Pot (connects Manchester Hole and Goyden Pot)
- Goyden Pot (Length 3.7 km)
- Back Steps (another way into Goyden Pot's main chamber)
- Church Pot (an alternative entrance for Goyden Pot, used as a flood exit)
- Limley Pot (another way into Goyden Pot)
- Guscott Pot (Length 103m)
- Frog Pot/Aquamole Series (Length 640m)
- New Goyden Pot (Length 2.2 km)
- Thrope Edge Pot (an alternative way into New Goyden Pot)
- Nidd Head NW Rising (Length 850m)
- Nidd Head SE Rising (Length 250m)
The entrances shown in bold are considered separate caves, while the others are different ways to enter those main caves.
Cave Exploration and Connections
So far, explorers have mapped about 8.3 kilometers (which is over 5 miles!) of passages in the Nidderdale Caves. Cavers and cave divers have managed to connect the caves all the way from Manchester Hole to New Goyden Pot.
Connecting some sections, like Goyden to New Goyden, requires special diving gear because parts of the passages are completely filled with water. These flooded sections are called sumps. Cave explorers have also worked hard to dig and open up new dry passages, for example, from New Goyden to Frog Pot. They are still trying to find and open a dry link from Frog Pot to Goyden Pot.
Cave divers have also explored the link between New Goyden Pot and the Nidd Head Risings, which is where the underground river reappears. At New Goyden Pot, divers have explored eight flooded passages with dry sections in between. At the Nidd Head Rising, they have dived over 850 meters, but there's still about 1 kilometer (over half a mile) of unexplored gap between the two caves!
How Water Flows Through the Goyden System
Understanding how water moves through these caves is called hydrology. It changes a lot depending on whether it's a normal day or if there's a flood!
Normal Water Flow
From Manchester Hole to Goyden Pot
Water from the moors above Angram and Scar House flows into these reservoirs, which then feed the River Nidd. Below the Scar House dam, the River Nidd flows east, then south. Soon after, it disappears underground into small cracks in the limestone rock. All this water then enters the large stream passage of Manchester Hole.
Inside Manchester Hole, the underground stream flows through an impressive passage to the Main Chamber. Here, the stream flows among fallen rocks and then enters a low, narrow area called 'the grovel'. After this, the passage gets bigger again in Fossil Passage. The stream continues to a section called 'the duck', where it makes a sharp turn and flows through a tight crawl with very little air space. Finally, the stream enters a flooded section, or sump, which connects to Goyden Pot.
From Goyden Pot to New Goyden Pot
In Goyden Pot, the water flows through many cracks in the rock, sometimes splitting into different directions. These streams quickly join up again and flow over large boulders in the Goyden Main Chamber. The water then flows along a huge passage, which can be 25 meters (about 82 feet) high in places! This passage leads to a series of sumps (flooded sections).
After passing through several sumps, the river reaches Bridge Hall. A small stream joins here, possibly from another passage. The river then flows through more sumps, eventually connecting with the Aquamole series, which can be entered from Frog Pot. The last sump in this section connects with New Goyden Pot.
From New Goyden Pot to the Nidd Head Risings
The water flowing from New Goyden Pot travels through a large, round passage. A significant amount of extra water joins from Frog Pot. The combined water then flows through a short, low flooded section called Middle Sump. After this, the water enters another series of sumps. Divers have explored beyond the first sump through seven more!
The water from the furthest explored point in New Goyden Pot travels just over a kilometer (0.6 miles) to the furthest explored point of the Nidd Head Resurgence. The River Nidd actually reappears from three places: the North West Rising, Main Rising, and South East Rising. Most of the water comes from the Main Rising, which divers have explored for over 850 meters (0.5 miles). The North West and South East Risings are also thought to connect with the Main Rising.
After combining, the river is joined by How Stean Beck and flows down Nidderdale to Gouthwaite Reservoir.
Flooding in the Goyden System
The Goyden system can flood when there's too much water overflowing from the Scar House dam. This can happen not only after heavy rain but also because of strong winds! If the wind blows hard from the west on a full reservoir, it can create waves that push water over the dam. This means the caves can flood even when it hasn't rained!
When there's a flood, the amount of water flowing down the valley is too much for Manchester Hole to take in. So, most of the water flows past Manchester Hole and directly into Goyden Pot's main entrance. Old, unused entrances can also open up during floods, letting more water into the caves.
The increased water flow causes the far end of Manchester Hole to flood very quickly. Water also rushes into Goyden Pot's Main Chamber from higher passages. This swollen river flows through the system, and because some passages are narrow, the water backs up and floods the entire system.
During severe floods, water can even burst out of Church Pot, Limley Pot, and New Goyden Pot, while Guscott Pot and Frog Pot still take in water. In the most extreme floods, the River Nidd can rise high enough to flow into Manchester Hole's main entrance!
The Geology of the Caves
The caves in Upper Nidderdale are truly unique in the UK because of their geology.
- Underground Location: Much of the cave system is found deep beneath the valley floor, often covered by layers of rock called Millstone Grit or Upper Yoredales.
- Rock Structures: The caves have formed across different geological features, including an anticline (a fold in the rock that looks like an arch) and several faults (cracks in the Earth's crust).
- Erosion: In Manchester Hole, water has worn away the base of the limestone and cut into the rock layers underneath.
- Wind and Flooding: Studies have shown that strong winds on Scar House Reservoir can cause significant overflow, leading to serious flooding in the caves further down the valley.
The limestone visible in Nidderdale is part of the Yoredale series, and almost all the cave system has formed within a narrow band of Middle Limestone, which is about 40 meters (130 feet) thick. This limestone appears in three main areas: one to the north (including Manchester Hole and Goyden Pot), a smaller one further south (including New Goyden Pot), and another nearly 2 kilometers (1.2 miles) further south (including the Nidd Head resurgences). Each of these limestone areas is separated on the surface by other types of rock.
The cave system is mostly contained within this Middle Limestone and has developed along the shale layers within the rock. The faults often mark where the sumps (permanently flooded sections) are located. Between these faults, there are large open passages.
It might seem surprising, but the system is mostly developed on one level. However, further exploration has revealed older, higher passages that were once active. Cave diggers have opened these up, creating dry connections between parts of the caves that divers had previously explored underwater.
The caves also show off some amazing fossils and chert beds (a type of hard rock). You can see fine examples of chert bands in Goyden Pot's Main Stream Passage. Impressive examples of Productus Giganteus fossils are found in Manchester Hole, and fossilized coral and many crinoids (ancient sea creatures) are clearly visible in Goyden Pot.
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