Hell's Mouth (Cornish: Ganow Yfarn) is situated northeast of

Gwithian Gwithian ( kw, Godhyan) is a coastal village in west Cornwall, England. It is three miles (5 km) north-east of Hayle and four miles (6.5 km) east of St Ives, Cornwall across St Ives Bay. Gwithian is in the civil parish of Gwinear-Gwi ...

on the

South West Coast Path The South West Coast Path is England's longest waymarked long-distance footpath and a National Trail. It stretches for , running from Minehead in Somerset, along the coasts of Devon and Cornwall, to Poole Harbour in Dorset. Because it rises a ...

in the county of

Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...

, England, UK. The land is owned by the

National Trust The National Trust, formally the National Trust for Places of Historic Interest or Natural Beauty, is a charity and membership organisation for heritage conservation in England, Wales and Northern Ireland. In Scotland, there is a separate and ...

. It is part of a group of cliff faces in the area, with a café not far from the edge. In 2011 a jogger on the Cornish Coastal Path noticed cracks in the rock, which is made up of

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology. ...

s and

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

s of the Porthtowan Formation and

slate Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. It is the finest grained foliated metamorphic rock. ...

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, p ...

s of the Mylor Slate Formation from the

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

. The route of the path was diverted as the cracks enlarged. On 23 September approximately of rock fell into the sea. Unusually the

rockfall A rockfall or rock-fallWhittow, John (1984). ''Dictionary of Physical Geography''. London: Penguin, 1984. . is a quantity/sheets of rock that has fallen freely from a cliff face. The term is also used for collapse of rock from roof or walls of min ...

was captured on video.

References

Cornish coast Tourist attractions in Cornwall {{Cornwall-geo-stub