Fingal's Cave is a sea cave on the uninhabited island of Staffa, in the Inner Hebrides of Scotland, part of a National Nature Reserve owned by the National Trust for Scotland. It is formed entirely from hexagonally jointed basalt columns, similar in structure to (and part of the same ancient lava flow as) the Giant's Causeway in Northern Ireland and those of nearby Ulva. In both cases, the cooling surface of the mass of hot lava cracked in a hexagonal pattern in a similar way to drying mud cracking as it shrinks, and these cracks gradually extended down into the mass of lava as it cooled and shrank to form the columns, which were subsequently exposed by erosion Romantic composer Felix Mendelssohn visited in 1829 and wrote Die Hebriden (in English, Hebrides Overture Opus 26, commonly known as Fingal's Cave overture), inspired by the weird echoes in the cave. Mendelssohn's overture popularized the cave as a tourist destination.