10 Breathtaking Basalt Columns Around the World

Basalt columns are natural pillars of hardened lava created by the contraction of volcanic rock as it cools. These columns are often shaped like hexagons, pentagons, or octagons due to the cooling process—that sometimes occurs over a century—and they can form as vertical cliffs or terraced steps, occasionally descending directly into the ocean.

What Is a Basalt Column?

Basalt columns are created by the cooling and contracting of lava—made of 90% basalt—which causes the ground to crack into long, geometric columns. This process is called columnar jointing.

In a 2018 study, researchers at the University of Liverpool replicated the formation of these rocks, finding that fracturing occurs at 194 to 284 degrees Fahrenheit below the point at which magma crystallizes into rock (1796 degrees). That means some of the world's most famous basalt columns, like those at Giant's Causeway in Northern Ireland and Devils Postpile in California, formed at temperatures between 1544 and 1634 degrees.

From Mexico to Namibia, here are 10 places to admire these fascinating geologic wonders.

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Giant's Causeway

Hexagonal basalt columns descending into sea on Northern Ireland coast — Chiara Salvadori / Getty Images

Giant's Causeway is perhaps the world's most extraordinary and well-known example of basalt columns. Some 50 to 60 million years ago, a volcanic plateau of molten basalt formed on the north coast of Northern Ireland, and as it cooled, the hardening lava cracked into tidy hexagonal, columnar tiles that now border and descend into the sea.

A UNESCO World Heritage site and national nature preserve (serving as a haven for marine life and seabirds), Giant's Causeway sees about a million people per year. Its name hails from ancient folklore: Before humans knew much about geology, they believed that the footsteps of giants caused the geometric cracks.

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Basaltic Prisms of Santa María Regla

Water rushing down tall and columnar basalt joints, forming rainbow — CassielMx / Getty Images

Water rushing over the Basaltic Prisms of Santa María Regla makes the ancient pillars look especially surreal. These polygonal columns range from 100 to more than 150 feet tall. They contain a ravine with water flowing from the San Antonio Dam, often causing a rainbow at the base of two waterfalls. This tourist attraction in Hildago, Mexico is enjoyed via walkways and hanging bridges.

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Devils Postpile National Monument

Low-angle view of tree-topped, columnar basalt cliff formation — LucynaKoch / Getty Images

Devils Postpile National Monument, near Mammoth Mountain in California, is one of the most fantastic displays of basalt columns in the United States. Apart from the site's regal appearance—a vertical, tree-topped cliff composed of long and symmetrical, interlocking pillars thought to be between 400 and 600 feet thick—the formation has had a whirlwind history. It was once included in Yosemite National Park, then removed due to the discovery of gold in the area, then almost demolished for a hydroelectric dam, saved by the legendary John Muir, and then—finally—protected as a national monument. This beautiful basalt formation is believed to be relatively new, created within the past 100,000 years.

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Fingal's Cave

Scotland's Fingal's Cave and Northern Ireland's Giant's Causeway emerged through the same Paleocene-era volcanic event. However, the former offers a unique viewing experience. Here, on the uninhabited island of Staffa, the basalt columns line the walls of a sea cave like blocky stalactites made of hardened lava.

The cave is 72 feet tall, 270 feet deep, and known particularly for its natural acoustics, which once inspired 19th-century composer Felix Mendelssohn to write an overture in its name. Visitors can experience the bizarre echoing and explore the otherworldly scene by walking on footpaths along the columns.

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Svartifoss

Large waterfall flanked by columnar jointed volcanic rock — FEBRUARY / Getty Images

Another basalt-column cliff decorated by falling water, Svartifoss in southern Iceland's Vatnajökull National Park is called "black waterfall" in Icelandic due to the dark color of the volcanic rock. The basalt formation, surrounded by Iceland's signature lush greenery, has inspired architectural works like the National Theatre in Reykjavik and was featured in Bon Iver's music video for the song "Holocene." You can reach Svartifoss via a short hiking track, but visitors should be wary of swimming as some of the basalt has cracked off from the cliff and created quite a sharp surface under the water.

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Takachiho Gorge

Boat paddling through volcanic river in shadow of basalt columns — Ippei Naoi / Getty Images

The basalt columns at Takachiho Gorge formed some 270,000 years ago due to four eruptions of the Mount Aso volcano. Since then, the Gokase River has cut through the columns, creating a narrow, V-shaped chasm through which beautiful blue-green water flows. Boats float down the four-mile gorge in the shadow of these 300-foot, red-tinted cliffs. The site has been protected as a National Scenic Spot and Natural Monument in Japan since 1934.

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Cape Stolbchatiy

Basalt columns partly submerged in the sea — HomoCosmicos / Getty Images

The cliffs at Cape Stolbckatiy on Kunashir Island, between Russia and Japan, are similar to Giant's Causeway. The rocks crack in the same hexagonal shape as the UK country's star attraction and create precipitous, 150-foot-tall seaside cliffs three times the height of Giant's Causeway. In certain places, the gray basalt columns descend diagonally like steps into the ocean and crop up offshore as rocky islands. An eruption of the nearby Mendeleev Volcano created these formations named after the Russian word for “columnar."

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Organ Pipes

Named for how they resemble organ pipes, these Namibian rocks—some more than 15 feet tall—are about 150 million years old. They're located near another volcanic feature, Burnt Mountain, whose solidified lava flow is a popular subject for photographers. Both formations have an extraordinary red tint that makes them appear fiery when the sun hits them in a particular way.

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Cape Raoul

Basalt columns covered in vegetation forming seaside cliffs in Tasmania — Posnov / Getty Images

Originally dubbed Basaltic Cape by its founders, the towering columns and shrubby cliffs on the southeast coast of Tasmania, Australia, were renamed Raoul by French explorers in the early 19th century. The formations were caused by a Jurassic-era volcanic event (about 185 million years ago) that is believed to have covered a third of the island. Erosion from the wind and sea has created a sort of noncohesive, craggy aesthetic.

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Hexagon Pool

Waterfall cutting through hexagon basalt rock formation into pool — Avi_Cohen_Nehemia / Getty Images

Swimming in a pool surrounded by steep, 15-foot basalt cliffs is a once-in-a-lifetime experience to be had in Israel's Yehudiya Forest Nature Reserve. Most of the columns that contain the 65-by-100-foot Hexagon Pool—a scenic swimming hole formed by the Meshushim Stream rushing grandly over the formations—are greater than a foot in diameter. This is the most spectacular of many basalt formations within the reserve, all caused by activity in the Golan Heights volcanic field.