After learning that Yellowstone was a supervolcano (one capable of essentially exploding into an eruption thousands of times larger than that of a mild-mannered, glasses-wearing volcano), geologists were rightly curious about how many other apocalyptic magma cannons had been built over by oblivious engineers, resort planners and goat-footed Hollywood directors. The answer is at least six.
The Los Alamos National Laboratory, which housed the development of the Manhattan Project, was built almost directly above a supervolcano dubbed Valles Caldera (presumably so if the atomic bomb turned out to be a failure, we would still get to see something explode). Despite its age (1 to 2 million years), the volcano is still showing subterranean activity, which, despite sounding like a compliment you would pay a septuagenarian who can get an erection without having to take beta blockers and change his underpants, means that the thing could technically erupt at any given time.
Witold Skrypczak / Getty
Silent but world-breaking.
Tanegashima Space Center, the largest rocket facility in Japan, sits on an island very close to the sea floor supervolcano Kikai Caldera, because those goddamned rockets are going into space one way or another. Kikai had a catastrophic eruption about 6,000 years ago, but it is still active (with smaller eruptions occurring as recently as 2004). As such, it is monitored closely by the Japan Meteorological Agency, because if a screaming explosion of power bursts out of the middle of the ocean and threatens to demolish their space program, they need to have enough time to page Gamera at a reasonable hour.
When they're not dodging giant sinkholes, civil war, earthquakes and hurricanes, residents of Guatemala City sit around wondering which one of the four volcanoes surrounding the city is going to melt them with boiling rock. However, they can't see Atitlan Caldera, a supervolcano 73 miles away. It's currently active, but it isn't being monitored, because evidently Guatemala polices all of its natural disasters with the honor system.
Steve O'Meara / Volcano World
"Oh yeah, that's got a few more centuries left. Mas cerveza, por favor."
Mammoth Lakes, in California's Central Valley, is home to the Mammoth Mountain Ski Area, as well as thousands of people who had no idea that they were living above an active volcano (cue slide whistle). It's nestled within the Long Valley Caldera, grenaded into the Earth like the GoldenEye cradle when the volcano blew up several thousand years ago. People figured that the steam vents, hot springs, mineral deposits and tectonic shifts were all just part of living in California, much in the same way that drowning is just part of living at the bottom of the ocean.
Jerry Dodrill / Oregon State
Left: tranquil beauty. Right: Everything that tranquil beauty will destroy when it explodes.
The Phlegraean Fields is a massive area around southern Italy that is essentially the T.G.I. Friday's of volcanic activity. It contains Mount Vesuvius, responsible both for melting the ancient Roman city of Pompeii and for splashing tons of fat people at Busch Gardens. For centuries, it seemed like its exploding days were done, but scientists now know that the area is a supervolcano caldera that might be just a few years from hate-spraying a molten rock fart all over southern Italy.
Newhall and Dzurisin, via Oregon State
"I should have known that that meatball sub was a bad idea ..."
The majority of Peter Jackson's Lord of the Rings trilogy was filmed on New Zealand's North Island, home to about 80 percent of the population (and to Ruapehu Volcano, which, coincidentally, served as Mount Doom). The North Island also contains Taupo Caldera, one of the most active supervolcanoes in the world. Taupo Caldera is largely contained beneath Taupo Lake and is responsible for belching out the most terror-shit-inducing eruption the planet has experienced in the past 5,000 years. It's still churning out hits like the Rolling Stones, staying active with smaller eruptions that throw up cinder cones and clouds of ash every time a bearded child on a Middle-Earth pilgrimage stumbles too close and provides it with a virgin sacrifice.
Laurie Noble / GNS Science
On the left, Mount Doom. And on the right, its drunken, abusive grand-uncle.