Volcanoes have caused incalculable destruction throughout history but even the most massive lava blaster has a heart. Volcanic plugs (the eroded cores of extinct volcanoes) are all that remain of some of the Earth’s most fearsome, fiery fumaroles after many millions of years of wind, water and weathering.
Devils Tower, Wyoming, USA
One of the most famous volcanic plugs and the first declared United States National Monument, Devils Tower rises 1,267 feet (386 m) from the rough terrain of northeastern Wyoming state. Most geologists estimate Devils Tower to have formed at least 50 million years ago, but a firmer fix on the time and even the method of formation remain problematic as most of the associated rock formations have eroded away.
The polygonal porphyry columns that help define the sides of Devils Tower are confirmation of its volcanic origin, while providing the approximately 4,000 hikers who complete the near-vertical ascent to its summit each year with an unforgettable rock-climbing experience.
The Pitons, Saint Lucia
Looking like stand-in scenery for Lord Of The Rings, the Pitons rear up from the coast of St. Lucia like the two last teeth of a VERY large shark. Gros Piton stands 2,530 ft (771 m) tall while its neighbor Petit Piton is just slightly smaller at 2,438 ft (743 m) tall. St. Lucia must have been the ultimate anti-tourism “hotspot” back in prehistory when the worn-away volcanoes that produced the Pitons were at their fire-breathing best. The Pitons don’t just dominate St. Lucia’s scenery, they’re a part of the Caribbean island’s culture as well. Be sure to enjoy a Piton beer next time you visit… in fact, make it two!
Ailsa Craig, Scotland
Rising 1,110 feet (340 m) above the breathtakingly chill waters of the outer Firth of Clyde, the now-uninhabited island of Ailsa Craig is a volcanic plug marking the location of an ancient volcano last active around 500 million years ago. The ruggedly pyramidal isle’s oft-precipitous slopes feature exposed columnar basalt formed when magma in the core of the volcano cooled and crystallized.
Ailsa Craig’s cold, hard heart doesn’t just keep this ancient volcanic plug extant when everything around it has long eroded away. Curling’s top skips & sweepers know the best “rocks” are those ground from fine-grained Ailsa Craig Common Green and Blue/Red Hone granite by Kays of Scotland.
Sigiriya Rock Fortress, Sri Lanka
Spectacular Sigiriya (Lion’s Rock) in central Sri Lanka may have been inhabited since prehistoric times. The rock formation and the surrounding area underwent lush landscaping and extensive building in the 5th century. Formed from a very ancient volcanic plug of indeterminate age, Sigiriya soars 1,214 ft (370 m) above sea level and can be seen from quite a distance as there’s nothing like it on Sri Lanka’s central plains.
Erosion has undercut Sigiriya’s base in some areas, giving it a mushroom shape from some vantage points. The enormous igneous rock formation made an ideal, easily defended fortress and hosted a Buddhist monastery up until 14th century.
The Nut, Tasmania
The Nut is a steep-sided volcanic plug that anchors one end of the bay fronting Stanley, Tasmania. Though The Nut’s official name is Circular Head, bestowed upon it in 1798 by explorers Bass & Flinders, most just call it The Nut and nobody really complains. Only 469 ft (143 m) tall, The Nut still affords a picture postcard perfect view of Stanley and the surrounding area as it’s the only high point around.
Steep sides notwithstanding, a well-worn footpath leads to the flat-topped summit of The Nut and, of course, back down again. If that’s too much trouble, a ski-resort style chair lift offers those with no fear of heights one of the most scenic trips around.
Taung Kalat, Myanmar
Taung Kalat is a 2,417 ft (737 m) tall volcanic plug located in central Burma. The steep-sided pedestal rock is topped by a centuries-old Buddhist monastery that can be reached by climbing 777 steps.
The monastery crowning Taung Kalat occupies almost every bit of available space on the summit. Visitors are advised not to bring meat with them as doing so could offend the “nats” – disaffected spirits who occupy the site. There’s also a practical reason: dozens of macaque monkeys who mob exhausted tourists who manage to reach the summit.
Shiprock, New Mexico, USA
Shiprock is a jagged remnant of an ancient volcano’s throat located in extreme northeastern New Mexico. The formation looms 1,583 feet (482.5 m) over an eerie desert landscape that has been steadily eroding away since the magma that formed Shiprock began to cool about 27 million years ago.
Shiprock got its name in the mid-nineteenth century when travelers noted its resemblance to a huge clipper ship, and it was first successfully climbed in 1939. The rock formation is sacred to the Navajo Nation and figures strongly in their most cherished origin myths and legends. Out of respect for the Navajo people, climbing Shiprock has been expressly forbidden since 1970.
Kapsiki Peak, Cameroon
Located in an otherworldly landscape near Rhumsiki village in Cameroon’s Far Northern Region, Kapsiki Peak is perhaps the most striking of several sharply eroded volcanic plugs. It’s also one of the tallest volcanic plugs on Earth, measuring a nosebleed-inducing 4,016 ft (1,224 m) in height.
Kapsiki Peak has a noticeably phallic appearance, a fact noted by the native tribes in the region. This distinctive characteristic has attracted barren women to the formation for many centuries, and continues to attract tourists in the modern day.
Trosky Castle, Czech Republic
If you were a medieval warlord looking to build a castle, the pair of basalt volcanic plugs in the Czech Republic’s Český Ráj (Bohemian Paradise) would be a great choice – and so it was, between the 14th and 17th centuries when Trosky Castle was built, rebuilt, and rebuilt yet again.
Though not especially tall, the 154 ft (47 m) tall Baba (Old Woman) and 187 ft (57 m) tall Panna (Young Maiden) provide excellent vantage points for keeping an eye on tenant farmers and invading armies.
Legend has it that there’s buried treasure hidden inside Trosky Castle; the fruits of a raid on the nearby Opatovice monastery. Supposedly the treasure was secreted in an underground chamber sealed by a huge boulder, subsequently buried in rubble and scree. Sounds like the plot of the next Indiana Jones movie – the producers will at least have a spectacular location to work with!
Morro Rock, California, USA
The knobby, rounded volcanic plug known as Morro Rock has been a familiar landmark for many generations of Californians. Rising to a height of 581 feet (177 m), the formation was named in 1542 by the Portuguese explorer Juan Rodriguez Cabrillo. Though quarried for stone used to build the Morro Bay Breakwater, efforts by environmentalists to protect and preserve the rock came to fruition in 1968 when the state government created the Morro Rock State Preserve.
Unlike many famous volcanic plugs, Morro Rock doesn’t stand alone though it does claim seniority by virtue of being the tallest of the so-called Nine Sisters of San Luis Obispo County. It’s a reminder that the California coast has always been a geologically active region though these days residents need not fear any new volcanic eruptions.
Like most of us, volcanic plugs were wild & restless in their youth but with the passage of age, settled down and mellowed out – and that’s a good thing. When it comes to volcanoes, it’s best to let sleeping dogs lie and don’t EVER think of… pulling the plug.


