Three Counties System
| Three Counties System | |
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Duke Street in Ireby Fell Cavern II
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| Location | North-West England |
| Coordinates | 54°12′25″N 2°30′23″W / 54.20699°N 2.506452°WCoordinates: 54°12′25″N 2°30′23″W / 54.20699°N 2.506452°W |
| Depth | 253 metres (830 ft) |
| Length | about 86.7 kilometres (54 mi) |
| Geology | Carboniferous limestone |
| Entrances | 53 |
| Difficulty | Various |
| Hazards | Various |
| Access | Various |
The Three Counties System is a set of inter-connected limestone solutional cave systems spanning the borders of Cumbria, Lancashire, and North Yorkshire in the north of England. The possibility of connecting a number of discrete cave systems in the area to create a single super-system that spans the county borders was first proposed by Dave Brook in 1968, and it was achieved in 2011. The system is currently over 86 kilometres (53 mi) long, making it the longest in the UK and the twenty seventh longest in the world, and there continues to be scope for considerably extending the system.
The Three Counties System most southerly entrance is currently Large Pot (54°11′11″N 2°29′18″W / 54.186439°N 2.488420°W, NGR SD 6281 7685) on the northerly flank of Kingsdale in North Yorkshire, and the most northerly entrance is currently Bull Pot of the Witches (54°13′35″N 2°31′10″W / 54.226398°N 2.519514°W, NGR SD 6623 8131) beneath Barbon Low Fell in Cumbria – a distance of almost 5 kilometres (3 mi). Between the two, the system passes beneath Ireby Fell and Leck Fell which are in Lancashire.
The system runs mainly north-south, its western extent being limited by the Craven Fault which truncates the limestone exposure, and the eastern extent where the limestones are conformable overlain by younger rocks. Streams flow from the higher topography from the east and sink into swallet holes at the edge of the limestone. The Three Counties System contains a number of major subterranean streams, all of which combine to resurge at Leck Beck Head above Cowan Bridge. At the northern end, swallets in Barbondale close to the Dent Fault drain south-west through Bull Pot of the Witches, and the water enters the Ease Gill Caverns system in Lancaster Hole; most of Ease Gill Beck to the south drains into the extensive Ease Gill Caverns, although some drains into Link Pot and thus into the bottom of Pippikin Pot; most of Leck Fell drains into the Leck Fell Master Cave, which is part of Lost Johns' Cave, although some drains into Gavel Pot, and some into Notts Pot; Ireby Fell in the south drains into Notts Pot. All these streams eventually reach the phreatic zone where exploration is only possible by cave diving. Some small streams in the south of The Three Counties System are known to resurge at Keld Head in Kingsdale, the next valley to the south.
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Wikipedia