The Longwood Swallet is a cave near Charterhouse, in the Carboniferous Limestone of the Mendip Hills, in Somerset, England. The cave is part of the Cheddar Complex SSSI and is connected to August Hole.
| Longwood Swallet | |
|---|---|
 | |
  | |
| Location | Charterhouse, Somerset, UK |
| OS grid | ST48615571 |
| Coordinates | 51°17′54″N 2°44′18″W / 51.298229°N 2.7384°W |
| Depth | 175 metres (574 ft) |
| Length | 1.65 kilometres (1.03 mi) |
| Elevation | 213 metres (699 ft) |
| Discovery | 1944 |
| Geology | Limestone |
| Entrances | 1 |
| Hazards | Frequent flooding |
| Access | Restricted |
| Cave survey | Geological Conservation Review/UBSS |
| Registry | Mendip Cave Registry[1] |
It is 1.65 km in length and reaches a depth of 175m.[2]
The cave was discovered in September 1944 by boys from Sidcot School.[3]
The picture shown is not the Longwood Swallet, it is Longwood Valley Sink. Longwood Swallet's entrance is lidded concrete block construction. A (non-free) picture of Longwood Swallet entrance is available here
The cave is locked and access is controlled by the Charterhouse Caving Company. There is a warning sign posted at the entrance to the cave about flooding. This has always been a problem, but is more pronounced due to the extraction of water from the spring at Charterhouse. When the pumps owned by Bristol Water stop this can cause a flood wave to travel down the stream and into the cave.[4]