Rat Hole, Gaping Gill

Rat Hole
Entrance to Rat Hole
Showing location of Rat Hole in North Yorkshire
Location	Ingleborough, North Yorkshire, UK
OS grid	SD 7509 7273
Coordinates	54°08′59″N 2°22′58″W / 54.149745°N 2.382734°W / 54.149745; -2.382734Coordinates: 54°08′59″N 2°22′58″W / 54.149745°N 2.382734°W / 54.149745; -2.382734
Depth	107 metres (351 ft) (To floor of Gaping Gill Main Chamber)
Length	200 metres (660 ft)
Elevation	403 metres (1,322 ft)
Discovery	1909
Geology	Carboniferous limestone
Entrances	2
Difficulty	V
Hazards	water, verticality
Access	Permit

Rat Hole is one of the entrances to the Gaping Gill cave system, located in the north bank of Fell Beck 30 metres (33 yd) upstream of Gaping Gill Main Shaft. A small, awkward, tube-like passage descends into a stream passage, and hence to a 100-metre (330 ft) shaft into Gaping Gill Main Chamber. The sharp and loose nature of the rock, and the quantity of water prevented full exploration for over 80 years, but the current route is described in one guide book as "a technical and exhilarating adventure". It lies within the designated Ingleborough Site of Special Scientific Interest.

Rat Hole is an inlet feeding the Gaping Gill main shaft complex.

A snug crawl of about 25 metres (82 ft) with a few bends passes a couple of minor inlets before dropping down a 3 metres (10 ft) climb. The passage below almost immediately joins a stream passage flowing from the left, carrying the Rat Hole Sink water.

Upstream, easy going leads to the Rat Hole Sink entrance. Downstream leads after a few metres to a 5 metres (16 ft) pitch at the bottom of which the water disappears down a gully, the way on being across some chock stone boulders to the main pitch. A descent of this is objectively dangerous, as it takes all the water and passes areas of sharp, tottering flakes. The current route descends a few metres but then swings into the rift to the east. From here a pendulum traverse leads to a ledge overlooking the impressive adjacent Mousehole (pronounced /ˈmaʊzəl/) shaft.

Above the ledge an aven leads to a small inlet passage. Across the pitch, a traverse leads to a draughting passage which passes under two small avens before becoming too tight.

Mousehole terminates in a floor with a window through to the Gaping Gill rift, but the route deviates to the south and finishes on a large well-watered scoop-shaped ledge after a 49 metres (161 ft) descent. A short traverse to the east leads to the final 35 metres (115 ft) pitch, which lands in the Main Chamber.

Rat Hole Sink is located 10 metres (33 ft) upstream of the main entrance where the water sinks. The entrance is normally covered with a grating. Below this a squirm downwards leads straight into the upstream passage of Rat Hole. When the stream is diverted, Rat Hole Sink provides easier access to the Rat Hole pitches than the traditional entrance.