Category 10: Fire & Ice

The UK and Ireland enjoy low tectonic activity and a temperate climate now, but we have had an explosive and, at times, very chilly history. From glaciations to volcanic eruptions, these sites represent some of the most dramatic events in our geological past.
Click on the links below to find out about each Geosite:
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Arthur's Seat and Salisbury Crags
Edinburgh, Scotland Arthur's Seat was formed by an extinct volcano system, later eroded by a glacier. The Arthur's Seat Volcano Site of Special Scientific Interest is designated to protect its important geology, grassland habitats and uncommon plant and animal species. |
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Cwm Idwal & Darwin’s BouldersSnowdonia/Eryri, Wales Cwm Idwal is a hanging valley in northern Snowdonia, North Wales and is a spectacular product of glaciation. It comprises volcanic and sedimentary rock which was laid down in a shallow sea and later folded to produce the Idwal syncline. ![]() |
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GlencoeLochaber, Highlands, Scotland The beautiful Glencoe is all that remains of an ancient super-volcano, long since extinct. The landscape has since been shaped by glaciation during the last ice age. ![]() |
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Parallel Roads of Glen RoyLochaber, Highlands, Scotland Located in Lochaber Geopark, the ‘Roads’, shorelines of a late-glacial ice-dammed lake, led to a famous exchange between Charles Darwin and the Swiss palaeontologist, Louis Agassiz. |
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Drumlins of Clew BayCounty Mayo, Ireland Clew Bay is a good example of a 'drowned drumlin' landscape where the drumlins appear as islands in the sea, forming a 'basket of eggs' topography. |
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Borrowdale volcanics & Crinkle Crags
Cumbria, England These volcanics make up most of the mountains at the head of Borrowdale, including Scafell Pike and Great Gable. Crinkle Crags is a fell in the English Lake District which forms part of two major rings of mountains, surrounding the valleys of Great Langdale and Upper Eskdale. |
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Slieve Gullion, Mountains of MourneCounty Armagh, Northern Ireland The Slieve Gullion ring complex geosite crosses the Ireland/Northern Ireland border, mid-way between Dublin and Belfast. It was one of the first ring dykes described in scientific literature in the early 1930s and has been considered a classic ring dyke since then. |
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Elgol Minor IntrusionsSkye, Inner Hebrides, Scotland These minor intrusions form part of the magma / wet-sediment interactions seen at Elgol on the Isle of Skye. |
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Hallival and Askival Layered IntrusionsRum, Inner Hebrides, Scotland Located on the Isle of Rum, the large steps in the mountainsides are individual units of the gabbroic layered series, each representing a fresh pulse of magma entering the magma chamber. |
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BenbulbenCounty Sligo, Ireland Ireland’s very own table mountain is located in County Sligo. Shaped during the ice age, this area is a protected site, designated as a County Geological Site by the Sligo County Council. ![]() |