The US Army built a nuclear-powered city inside the Greenland ice sheet as cover for a plan to run 600 missiles through 4,000 km of tunnels beneath it; Denmark found out in 1997

In 1959, the US Army started drilling into a glacier in Greenland. According to the Atomic Heritage Foundation's Nuclear Museum, what emerged from that dig was Camp Century, an underground base powered by a portable nuclear reactor, publicly sold as a research station. That was not all. It was a cover for a much larger plan, codenamed Project Iceworm.

If you grew up thinking Cold War missiles were mostly hidden in Kansas wheat fields, this story may surprise you.

An ice city with a barbershop and a hidden agenda
Camp Century looked like an engineering feat, on paper. According to the Atomic Heritage Foundation, soldiers lived in a network of 26 tunnels cut into the ice and roofed with steel arches, with dormitories, a hospital, a chapel and even a barbershop, all powered by a small nuclear reactor that ran 24 hours a day. Journalists came to visit, and the base appeared in the magazine’s May 1962 issue, as an engineering marvel, according to National Geographic’s retrospective on the site. The real purpose, known to almost nobody outside a small circle of Army planners, was to show that tunnels could be built inside a moving glacier and scaled up into a much larger system.


The photographs that later ran in National Geographic were taken during a period when the station was being framed as a triumph of polar engineering, even as the reactor leak had already exposed how fragile the setup was. By the time of the magazine’s May 1962 feature, the camp had 15 escape hatches, a cut-and-cover trench system, and the aura of a futuristic city built to normalize an otherwise classified military experiment.

The real plan: 600 missiles under the ice
That bigger plan was Project Iceworm. Army planners envisioned a tunnel network that would stretch across 52,000 square miles, three times the size of Denmark, with 60 launch control centers and 11,000 soldiers living under the ice full time, deploying as many as 600 modified Minuteman missiles nicknamed "Iceman," according to the Atomic Heritage Foundation. According to a peer-reviewed history of the project by Danish scholar Nikolaj Petersen, published in the Scandinavian Journal of History, the plan called for launch complex floors that sat 28 feet below the surface, with missile clusters spaced four miles apart across a tunnel system that, according to outside historical accounts of the project, totaled roughly 4,000 kilometers, or 2,500 miles, in length.

Today, for an American reading this, the scale is worth pausing on. It was not just one bunker. It was a plan to conceal a second, mobile, nuclear arsenal in the ice sheet of an allied country, largely without that country’s informed consent.

Denmark wasn't told the whole story
Greenland is part of Denmark, which is a NATO ally. The two countries signed a 1951 agreement allowing the US to build bases there but, according to the Atomic Heritage Foundation, that agreement never mentioned nuclear missiles, and when American officials informally floated the idea, Denmark’s leadership gave a deliberately vague, noncommittal answer. The US Army interpreted the silence as implicit approval and proceeded. The full extent of Project Iceworm remained classified until 1997, when the Danish Institute of International Affairs reviewed declassified files during an unrelated nuclear weapons controversy and published what had been planned under the ice.

Why the plan collapsed before Denmark ever learned the truth
Iceworm never put the missiles into the ice, and the Army had long since abandoned the system, well before the disclosure in 1997. Like all glaciers, the tunnels at Camp Century were already beginning to deform a few years after they were constructed. In 1963, engineers struggled to keep pace with the changing ice, and so the camp’s reactor was shut down, and the base was entirely abandoned by 1966, when it was engulfed by the glacier it was built inside, according to National Geographic.

The buried legacy nobody planned for
Here’s the twist: the most enduring thing Camp Century left behind wasn’t military. As an afterthought, in 1966 engineers drilled straight through the ice to bedrock and pulled out a tube of frozen soil. That sample was forgotten in a freezer for decades, until scientists rediscovered it. The soil contained preserved twigs, moss, and other plant remains, showing that this part of Greenland was ice-free and vegetated at least twice in the past few million years, with the last exposure about a million years ago, according to a 2021 study in the Proceedings of the National Academy of Sciences.

There’s also a more troubling legacy. Diesel fuel, wastewater, and low-level radioactive coolant from the reactor are said to be stored at the abandoned site of Camp Century, all left behind on the assumption that perpetual snowfall would bury it forever, according to the 2016 study, ‘The abandoned ice sheet base at Camp Century, Greenland, in a warming climate,’ in Geophysical Research Letters. The scientists found that, in a high-emissions warming scenario, the site could shift from snow accumulation to snow loss in about 75 years, exposing waste later this century and turning a Cold War secret into a live environmental issue for the US, Denmark and Greenland.