Creag Ghlas Laggan is a Marilyn

Marilyn (hill)

A Marilyn is a mountain or hill in the United Kingdom, Republic of Ireland or Isle of Man with a relative height of at least 150 metres , regardless of absolute height or other merit...

 on the Isle of Arran

Isle of Arran

Arran or the Isle of Arran is the largest island in the Firth of Clyde, Scotland, and with an area of is the seventh largest Scottish island. It is in the unitary council area of North Ayrshire and the 2001 census had a resident population of 5,058...

 in south-western Scotland

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

. It is the highest point of the seven-mile-long ridge

Ridge

A ridge is a geological feature consisting of a chain of mountains or hills that form a continuous elevated crest for some distance. Ridges are usually termed hills or mountains as well, depending on size. There are several main types of ridges:...

 of land that runs north-west to south-east between the A841 road

A841 road

The A841 road is the only A-road on the Isle of Arran and forms the island's primary transport route, as it connects all the major settlements on the island on its 50-mile course around the coast - Brodick, Lochranza, Blackwaterfoot and Whiting Bay...

 and the Sound of Bute

Sound of Bute

The Sound of Bute is a broad channel or sound separating the islands of Arran and Bute on the west coast of Scotland.The sound leads up from the lower Firth of Clyde passes the island of Inchmarnock and splits into the Kyles of Bute, Loch Fyne and round the north end of Arran into the Kilbrannan...

 in the north-eastern part of the island.

The best way up in terms of scenery is to follow the well-trodden and easily-graded path from Lochranza

Lochranza

Lochranza is a village located on the Isle of Arran in the Firth of Clyde, Scotland. The population, somewhat in decline, is around 200 people....

 to Bearradh Tom a' Muidhe at grid ref 962508, and strike south-east up the ridge from there. The shortest way up is a straight line from the parking area at Boguillie at grid ref 973483.

The hill has a remarkable variety of geology

Geology

Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...

. On its north-western slopes is the famous Hutton's Unconformity

Hutton's Unconformity

Hutton's Unconformity is any of various famous geological sites in Scotland. These are places identified by 18th-century Scottish geologist James Hutton as an unconformity, which provided evidence for his Plutonist theories of uniformitarianism and about the age of the Earth.-Theory of rock...

 in the Dalradian

Dalradian

Dalradian in geology describes a series of metamorphic rocks, typically developed in the high ground which lies southeast of the Great Glen of Scotland...

 metasediment

Metasediment

In geology, metasediment is sediment or sedimentary rock that shows evidence of having been subjected to metamorphism. The overall composition of a metasediment can be used to identify the original sedimentary rock, even where they have been subject to high-grade metamorphism and intense...

s. On the north-east shore can be found Carboniferous limestone

Carboniferous limestone

Carboniferous Limestone is a term used to describe a variety of different types of limestone occurring widely across Great Britain and Ireland which were deposited during the Dinantian epoch of the Carboniferous period. They were formed between 363 and 325 million years ago...

 and Permian

Permian

The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...

 desert deposits. At the south-eastern end is some Devonian

Devonian

The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...

 Old Red Sandstone

Old Red Sandstone

The Old Red Sandstone is a British rock formation of considerable importance to early paleontology. For convenience the short version of the term, 'ORS' is often used in literature on the subject.-Sedimentology:...

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Creag Ghlas Laggan offers stunning views towards Caisteal Abhail

Caisteal Abhail

Caisteal Abhail is a mountain on the Isle of Arran in Scotland.It is the northernmost Corbett on the island. The mountain forms the main part of a view known as The Sleeping Warrior due to its distinctive outline as seen from the mainland...

 and the other peaks such as Goat Fell

Goat Fell

Goat Fell is the highest point on the Isle of Arran. At 874 metres , it is one of four Corbetts on the island...

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