Noon's Hole

Noon's Hole (Sumera) – Arch Cave
Caver rigging the entrance of Noone's Hole
Location	Devenish, Co. Fermanagh
Coordinates	54°23′00″N 7°51′24″W / 54.383255°N 7.856665°W / 54.383255; -7.856665Coordinates: 54°23′00″N 7°51′24″W / 54.383255°N 7.856665°W / 54.383255; -7.856665
Depth	108 m (354 ft)
Length	3.7 km (2.3 mi)
Discovery	1895 onwards
Geology	Limestone
Entrances	2
List of entrances	Noon's Hole, Arch Cave
Difficulty	High
Hazards	Verticality & water

Noon's Hole (Irish grid ref H12684431) lies about 5 km northwest of the centre of Boho, in the townland of Old Barr in the parish of Devenish, County Fermanagh, close to the border with Boho parish. The cave is under part of the escarpment on the east side of the Glenade Sandstone uplands. At 81 m (266 ft), this pothole was thought to have the deepest shaft in Ireland, but this honour was passed to the nearby Reyfad Pot, which contains an entrance shaft of 88 m (289 ft). The continuation of the cave system (incorporating the Afternoon Series and High Noon's) contains 3.7 km (2.3 mi) of passage, and it connects to the resurgence at Arch Cave through three cave dives, making this system the 8th deepest in Ireland, at 108 m (354 ft).

Noon's Hole was previously called "Sumera", meaning "abyss", but gained notoriety and a new name in the 1820s, following the notorious murder of Dominick Noone, whose body was thrown into the cave. Ordnance Survey maps still use both names.

A Sumera is a bottomless pit, and locals initially treated Noon's Hole as a supernatural area, viewing it with suspicion and fear. However, in August 1895, the French cave explorer Édouard-Alfred Martel explored the cave for the first time, descending to 20 metres (66 ft). It was not until 1912 that a group called the Yorkshire Ramblers reached the bottom. Not discouraged by their equipment not having arrived from England, they made the descent of the complex 78 metres (256 ft) shaft using a 35 metres (115 ft) long rope ladder built from materials purchased from Fermanagh ships chandlers and timber merchants, hauling it up and down from the surface when the explorers found ledges to stand on. All they found at the bottom was a short passage leading to a sump. During the Easter of 1970, a group from the University of Leeds Speleological Association investigated the parallel shafts, and found that one led into 400 metres (1,300 ft) of passages they named the After-Noon Series.

In the meanwhile, cave divers had been pushing in Arch Cave from which the water from Noon's Hole resurges. In 1972 Martyn Farr and Roger Solari passed an 80 metres (260 ft) sump into a long canal, and then a 8 metres (26 ft) sump into a major extension which extended into the mountain for a further 1,500 metres (1,600 yd) to a third sump. The pair returned into 1973, and after a 49 metres (161 ft) dive they emerged into the After-Noon series of Noon's Hole.