Which volcano created the dramatic basalt columns of Fingal’s Cave in Scotland?

Fingal’s Cave formed from lava associated with the Mull volcanic centre in Scotland.

The sea cave is on the uninhabited island of Staffa in the Inner Hebrides. Its walls contain unusually regular hexagonal basalt columns, created when thick lava cooled and contracted. The columns formed during Paleogene volcanic activity about Paleogene volcanic activity about 60 million years ago, when the North Atlantic was opening.

The Mull volcanic centre was one of several major volcanic areas linked to the opening of the North Atlantic. Erosion later exposed the cooled basalt, and waves carved Fingal’s Cave into the columned lava flows. The cave became internationally famous after visits by figures including the composer Felix Mendelssohn.

The columns are sometimes casually described as “volcanic crystals,” but they are fractured basalt produced by cooling. Fingal’s Cave is not a separate volcano. Staffa is also often compared with Northern Ireland’s Giant’s Causeway, which formed through related Paleogene basaltic volcanism.