Mochras (sometimes known as ''Shell Island''), is a

peninsula A peninsula (; ) is a landform that extends from a mainland and is surrounded by water on most, but not all of its borders. A peninsula is also sometimes defined as a piece of land bordered by water on three of its sides. Peninsulas exist on al ...

lying west of

Llanbedr Llanbedr () is a village and community south of Harlech. Administratively, it lies in the Ardudwy area, formerly Meirionnydd, of the county of Gwynedd, Wales. History Ancient monuments at Llanbedr include Neolithic standing stones; the ...

Gwynedd Gwynedd (; ) is a Local government in Wales#Principal areas, county and preserved county (latter with differing boundaries; includes the Isle of Anglesey) in the North West Wales, north-west of Wales. It shares borders with Powys, Conwy County B ...

, Wales. It was formed after the River Artro was diverted by the Earl of Winchelsey in 1819 from its previous course where it entered the sea to the south of Mochras. Prior to this, access to the ancient settlement on the 'island' would have been through the village of Llandanwg, which is now across the estuary. Shell Island view 1985

Mochras is known for the wide variety of

seashell A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer usually created by an animal or organism that lives in the sea. The shell is part of the body of the animal. Empty seashells are often found washe ...

s that wash up on the beach, and for its wild flowers. It is said to have been connected to the mythical

Cantre'r Gwaelod , also known as or ( en, The Lowland Hundred), is a legendary ancient sunken kingdom said to have occupied a tract of fertile land lying between Ramsey Island and Bardsey Island in what is now Cardigan Bay to the west of Wales. It has been de ...

. Public vehicular access to the peninsula is only possible via a

causeway A causeway is a track, road or railway on the upper point of an embankment across "a low, or wet place, or piece of water". It can be constructed of earth, masonry, wood, or concrete. One of the earliest known wooden causeways is the Sweet ...

across the estuary of the River Artro when the tide is out. Access on foot is always possible from the adjacent Morfa Dyffryn beach, which extends for several kilometres south of Mochras. Access to emergency vehicles is available at any time through the neighbouring airfield. Mochras has a popular camp site which offers the opportunity to practise "wild camping" in pitches which are far from the nearest neighbour (and from toilet and other facilities). Camp fires are allowed on the beach; with only raised, contained fires and barbecues allowed on the campsite. The peninsula lies within the

Snowdonia Snowdonia or Eryri (), is a mountainous region in northwestern Wales and a national park of in area. It was the first to be designated of the three national parks in Wales, in 1951. Name and extent It was a commonly held belief that the na ...

National Park A national park is a natural park in use for conservation purposes, created and protected by national governments. Often it is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individua ...

, as a result of which the campsite closes from the end of October to the following March. During this period, local farmers bring their sheep from the lowlands to graze on the 'island'.

Geology

Mochras is significant for the UK earth sciences. The area consists of a low lying raised beach (which encompasses the nearby Llanbedr Airport) and it caused a sensation (in the geological community, at least), when the Institute of Geological Sciences (now known as the

British Geological Survey The British Geological Survey (BGS) is a partly publicly funded body which aims to advance geoscientific knowledge of the United Kingdom landmass and its continental shelf by means of systematic surveying, monitoring and research. The BGS he ...

) drilled a 1,938 m deep

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers ( strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostr ...

proving borehole at Mochras Farm between late 1967 and late 1969. Beneath the obscuring recent beach cover, the Mochras Borehole found relatively young

Tertiary Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the demise of the non- avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start ...

and

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Creta ...

rocks (including a well-developed Upper, Middle and Lower Lias section towards the base of the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

), faulted against the ancient

Cambrian The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ag ...

rocks of the

Harlech Harlech () is a seaside resort and community in Gwynedd, north Wales and formerly in the historic county of Merionethshire. It lies on Tremadog Bay in the Snowdonia National Park. Before 1966, it belonged to the Meirionydd District of the 1 ...

dome. In 1971, the vertical throw of the fault''The Llanbedr (Mochras Farm) Borehole''
IGS Report No. 71/18, HMSO London, 116 pp + figs, SBN 11 880213 5 was judged to be at least 4,500 metres (2¾ miles).

References

{{reflist

External links

The Official Shell Island Campsite WebsiteShell Island beach Guide
Llanbedr Peninsulas of Wales Landforms of Gwynedd Coast of Gwynedd Landforms of Snowdonia Seaside resorts in Wales

Geology

See also

References

External links