When lava pours out and cools slowly over time, a curious geometric pattern emerges: long columns of hexagonal basalt rock, sometimes forming cliffs that stretch hundreds of feet into the air. These igneous rock formations can be found all around the world, from Ireland to Israel to Japan to California, each adding a fascinating structure to the landscapes and waterscapes in which they are settled.

It’s amazing to think that a violent eruption of lava however many thousands of years ago could result in something so symmetrical. It is the nature of basaltic lava cooling that allows this to happen: this lava is hotter and moves faster than other kinds. As it cools from the bottom up and from the center outward, long fractures form columns that at times take on astoundingly clear-cut hexagons. The whole process is calledcolumnar jointing.

These columns form in vast bunches and are often found near sources of water, along an island’s coast or in the middle of a river or stream. Take a look at some of the most magnificent basalt formations across the globe:

Giant’s Causeway in Ireland

Giant’s Causeway in Ireland (Photo: tamsindove/Shutterstock)

Giant’s Causeway on the northeastern coast of Ireland is perhaps the most famous set of basalt columns in the world. Somewhere around 40,000 basalt columns form steps along the raging Atlantic Ocean like puzzling staircase that leads out to the waves. The area, now a UNESCO World Heritage Site, is protected by the Department of the Environment for Northern Ireland. The landmark is so named because of an old legendthat explains the columns as being remnants of a huge road built by a giant. Supposedly, it once stretched all the way to Scotland.

Fingal’s Cave on the Isle of Staffa in Scotland

Fingal’s Cave on the Isle of Staffa off the coast of Ireland (Photo: dun_deagh/Flickr)

Directly across the sea, off the coast of Scotland, another set of basalt pillars looms tall over the ocean. The Scottish Isle of Staffa was created by the very same lava flow (it must have been quite the geological event). In the same ancient lore, another giant lived here, and the road connected them so that they could duel. The Scottish giant’s name was Fingal, and so the cave in the above photo was named after him.

Devils Postpile National Monument in California

The Devils Postpile in California (Photo: Greb Balzer/Flickr)

Ranking as “one of the world’s finest examples of columnar basalt,” according to the National Parks Service, this monument stretches 60 feet into the sky and boasts what the service calls “an unusual symmetry.” Devils Postpile was formed by a lava vent that was impeded, creating a large lake that eventually cooled into the long, hexagonal columns we observe today.

Hexagon Pool in Israel

A closer look at the intriguing rock formations at the Hexagon Pool in Israel (Photo: David Scaduto/Flickr)

At the bottom of a canyon, surrounded by a protected forest, is Israel’s Hexagon Pool, also known as Breichat HaMeshushim. A popular destination in northern Israel for hikers and swimmers, this pool was largely created thanks to the flowing of water over the cooling igneous rock. 

The hike through the forest down to the pool is what photographer David Brooks called “a little treacherous at times” — but the effort is worth the experience, one that many nature photographers dream to capture. 

Svartifoss Waterfall in Iceland

The Svartifoss Waterfall in Iceland’s Skaftafell National Park (Photo: Max Topchii/Shutterstock)

“Black Fall” in Iceland’s Vatnajökull National park features a stunning single waterfall amid contrasting dark columns. Being a land filled with volcanoes and igneous formations, Iceland has many examples of basalt columns, each one more alluring than the next. Whereas visitors can jump into the pool at Hexagon Pool in Israel, it is not recommended here — the bottom of the water is filled with sharp rocks as the waterfall erodes the columns and they fall. 

Takachiho Gorge in Japan

Takachiho Gorge in Japan (Photo: Filip Fuxa/Shutterstock)

This bright green gorge in southern Japan stands out on the list not only because of its hue but also because its cliffs are over 300 feet high. Water continues to run aplenty in this region, which is why plant growth has extended down through the columns. The breathtaking Manai Waterfall continues to erode the rock, which visitors can see for themselves by boat. 

Los Prismas Basálticos in Mexico

Prismatica Basalticos in Mexico (Photo: Lemonpink Images/Shutterstock)

A gorge lined with basalt columns, the Basaltic Prisms in Hidalgo, Mexico are known for the beautiful spring waterfall that flows through them. Towering 98 feet above the water below, the rocks have been uniquely shaped by the waterfall, appearing more like lumpy steps beneath the water. Visitors can explore by climbing and walking on the rocks and rinsing off in the waterfall — a truly immersing experience. 

Cape Stolbchaty in Russia

Cape Stolbchaty, Kunashir, Greater Kuril Islands (Photo: Eugene Kaspersky/Flickr)

On Kunashir Island among the Kuril Islands in Russia, volcanoes formed choppy basalt structures along the coast of the Sea of Ohotsk. The columns of Cape Stolbchaty, a UNESCO World Heritage Site, are 50 million years old. Walking along the top of the pillars, visitors can see tiny pentagons within larger pentagons — a truly geometric site.

Basalt Cliffs of Jeju Island in South Korea

Basalt Cliffs on Jeju Island in South Korea (Photo: Butch Dalisay/Flickr)

A volcanic island off the coast of South Korea, Jeju Island has wide expanses of basalt columns. The iconic Jusangjeolli Cliffs were formed over 100,000 years ago by a then-active volcano. 

“Though the Jusangjeolli Cliffs may not be one of the better known attractions on Jeju,” writes Darryl Cootes for The Jeju Weekly, “they are definitely one of the more mysterious and beautiful.”

Ghenh Da Dia in Vietnam

Ghenh Da Dia in Vietnam (Photo: Duc Den Thui/Shutterstock)

The columns of Ghenh Da Dia in Phu Yen, Vietnam, may be much smaller than the others on the list, but the bright and lively locale earns this formation a spot on the list. Whereas other groups of columns on the list take on a free-form shape filled with hexagons, the rocks here actually form a star pattern. Explorers can walk atop the rocks and enjoy a front-row view of the local fishermen. 

Los Organos of the Canary Islands in Spain

Los Organos in the Canary Islands of Spain (Photo: Ingo Ronner/Flickr)

Impossibly huge and daunting, the cliffs of Los Organos are named for the pipes of the musical instrument, and it’s easy to see why. Outlining La Gomera of the Canary Islands, the basalt rock reaches over 2,000 feet. A monumental wonder, Los Organos are truly dizzying to look upon.