This distinctive dome-shaped island-rock lies 10 miles (16 km) off the coast of South Ayrshire and rises sharply from the Firth of Clyde to a height of 340m (1114 feet).
Ailsa Craig, which comes from the Gaelic for 'Fairy Rock', is 1200m (1300 yards) long and 800m (900 yards) wide, with an area of 100 ha (245 acres). It is also known as Paddy's Milestone owing to its position as a landmark en route from Ireland. The island was the heart of an ancient volcano, dating from 60 million years ago, its rock exhibiting fine columnar structure and was renowned as the source of a rare and superior micro-granite used to fashion curling stones. Three types of micro-granite are recognised; namely Common Green, Blue Hone and Red Hone. By the late 19th Century the island had a population of 29 people, working in the quarries or the lighthouse, which was built in 1883-6 by Thomas Stevenson and his nephew David. Since the closure of the quarries and automation of the light, Ailsa Craig has been inhabited only by a sizeable and important colony of sea-birds. The island is home to one of the largest gannet colonies in the world, with more than 70,000 birds, and is designated as a European Special Protection Area. Kays of Scotland, based in Mauchline, still hold an exclusive lease to extract granite boulders for the manufacture of curling stones. They exercise this right approximately once per decade, to replenish their stock of raw material.
Ailsa Craig is the property of the Marquess of Ailsa, whose family has owned the island since 1560. It was offered for sale in 2011, with an asking price of £2.5 million and then again in 2014 at a reduced price of £1.5 million.
The island is accessible by boat from Girvan.