You won't believe the colonade geometry of the Fingal caves!
Some 60 million years ago, fresh lava met water and began to cool, causing it to contract and fissure. As water seeped into the cracks and accelerated cooling, rifts grew perpendicular to the lava flow and formed a procession of columns of all different sizes. The magnificent natural colonnade bears mostly six-sided structures, though some of the pillars have only three sides and others up to seven, depending on the rate of cooling. They stand up to 98 feet (30 m) high, flanking an arched ceiling that gives the cavern a cloistered feel.
As if carefully sculpted, the basalt structures lining Fingal's Cave in the Inner Hebrides are a spectacular display of geometry, born entirely of lava flows. The cave is a natural feature of tiny Staffa Island, which has less than a square mile (2.6 sq km) of uninhabited land. It's unknown if people ever settled on this island, or if it was only a traveler's stopover. The Vikings named it the Old Norse word for "pillars" in recognition of the linear basalt columns that reminded them of the log construction of their own homes.