Ailsa Craig

Ailsa Craig is a pluton, a volcanic upwelling from about 60 million years ago, along with similar hills on the nearby island of Arran. Typically a pluton has no erupting volcano, but magma wells up and shoulders aside pre-existing rock. It then cools very slowly into coarse-grained granite that is hard-wearing, so it persists long after surrounding features have eroded away. Plutons have formed throughout Earth's existence and this one arose in the Palaeogene, formerly called the Early Tertiary. In that period the continents came close to their present positions, the global climate cooled, and dinosaurs suffered mass extinction to be replaced by mammals. Then followed the ice ages, which scraped and polished the surface of Ailsa Craig, and transported boulders from it as far away as Pembroke and Donegal. Any Stone Age person stranded amid the frozen wastes would be sure to think: "Hey, what a colossal ice rink and helluva curling stone".

The island has fresh water but almost no topsoil, and it's a long way to bring sheep for grazing, so only intermittently was it inhabited. Around 1400 it was owned by the Cluniac monks of Crossraguel, and has been a bolthole for fugitives and landing-beach for fishermen and pirates. It's always been a nesting place for seabirds and stop-off for migratory flocks: the solan geese were hunted into modern times. Yet this remote spot once had a gasworks and two railways.

There are no scheduled ferries, and most visitors get here on a boat trip. Most trips are non-landing, circumnavigating to view the wildlife. Ailsa Craig is also within sea-kayaking range, but you're nine miles out, think about the changing conditions and the getting back.

Girvan is the usual point of departure for trips, see that page for details. McCrindle the main boat operator advertises year-round sailings. In reality, the weather and lack of customers make trips unlikely in winter.

Cruises of the west coast and Hebrides sometimes approach Ailsa Craig. One example is the Waverley, the world's last sea-going paddle steamer, which ranges around the Firth of Clyde in summer. This elderly vessel has had long spells hospitalised for repair, and it's a wonder she keeps going.

The landing jetty on Ailsa Craig is on the sheltered east side, just north of the lighthouse.