L:810
V:40

Caswell Valley Sink, Espalone, Ogof Carreg Mawr, Big Rock Cave, Ogof Maen Dynastur, Cave of the Rock of Mourning Water


NGR: SS 59611 88777
75 m.asl

Swansea , Gower
 map using leaflet map:
Sink Cave
Access No public access
Description 10m drop leads to sump, passable only after dry weather via a very tight squeeze to 'A complex maze of passages apparently with few redeeming features. Very flood prone'. Not satisfied with mere 3D maze areas, the survey boasts a 4D maze and the cave has numerous ends in chokes, avens, and sumps, one dived 20m to an impassable squeeze...
History Site descriptions go back to the Llandaff Charters of 695AD; dye tracing by Baynton; cave explored by Gower Caving Club, 1991, after 5 year dig. Revisited and resurveyed by original explorers, 2022
Hydrology Water connects to Caswell Bay Rising in 3 days. The flow rate was 150 gallons a minute (.011 cumec). Tests
Conservation
Survey
GCC 1991, G4 (incomplete)
2022, Rob Davies, Michelle Allison, Alex Lewis
References
Archaeologia CambrensisCI, pp.26-27, Clarence A.Seyler, Some place-names and folklore in Wales, 1951 [..Main Dynastur (a rock where the stream disappears underground...) and Espalone (cognate with Hepste - dry valley)..]
SWCC Newsletter 51, (1965) p.11
SWCC Newsletter 59, (1968) pp.29-31
SWCC Newsletter 62, (1969) p.46
Descent 101, p.10 (1991), Ogof Carreg Mawr
Speleotawe 1, p.37, Murton dig (1965)
Oldham, Caves of Gower
Descent 169, p.9 (2002), Progress at Caswell
Welsh Sump Index, 2006
Descent 288, p.11 (2022), Carreg Mawr surveyed
Search for further records Browse registry map
Cambrian Cave Registry entry 1157
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