Fingal's Cave Fingal's Cave Fingal's Cave is a sea cave on the uninhabited island of Staffa, in the Inner Hebrides of Scotland, known for its natural acoustics. The National Trust for Scotland owns the cave as part of a National Nature Reserve. It became known as Fingal's Cave after the eponymous hero of an epic poem by 18th-century Scots poet-historian James Macpherson. Fingal's Cave is formed entirely from hexagonally jointed basalt columns within a Paleocene lava flow, similar in structure to the Giant's Causeway in Northern Ireland and those of nearby Ulva. In all these cases, cooling on the upper and lower
Cave of the Crystals the Naica mine workings, the Cave of Swords (). It is located at a depth of , above the Cave of the Crystals, and contains spectacular, smaller ( long) crystals. It is speculated that at this level, transition temperatures may have fallen much more rapidly, leading to an end in the growth of the crystals. Giant Crystal Cave was discovered in April 2000 by miners excavating a new tunnel for the Industrias Peñoles mining company located in Naica, Mexico, while drilling through the Naica fault, which they were concerned would flood the mine. The mining complex in Naica contains substantial