In September 1944 the world's first full-scale plutonium reactor went critical beside the Columbia River, then shut itself down a day later. B Reactor made plutonium for Trinity and Nagasaki, ran on into the Cold War, and now takes visitors on free tours.
In the flat farmland of north-east North Dakota stands a four-sided concrete pyramid built to guide nuclear-tipped missiles against a Soviet attack. It cost billions, reached full readiness on 1 October 1975, and was ordered closed the next day.
In the Nevada desert there is a five-mile tunnel drilled to hold the nation's spent nuclear fuel for a hundred thousand years. It was never filled. After decades of fighting, billions of dollars and a vote in Congress aimed at one state, Washington is now looking for a different place to put the waste.
For decades the Soviet Union sprayed anthrax, plague and tularemia over animals tied to stakes on a remote island in the Aral Sea. Then the sea drained away, the island joined the mainland, and the pits where the leftover spores were buried became an international problem.
On the Croatian side of the border with Bosnia, a Cold War airbase was cut into a mountain so that MiG-21s could be hidden, fuelled and launched from inside it. In May 1992 the army that built it blew it up, and the mountain has been quiet, mined and half forgotten ever since.
Six white concrete domes stood on stilts off the southwest Florida coast, a solar-powered home built in the early 1980s by a retired oilman. Erosion left them in the open sea, and in 2017 and 2022 the hurricanes brought them down. They now lie under the Gulf.
In a bowl of desert outside Albuquerque stands a wooden structure as tall as a twelve-storey building, built almost without metal so that a B-52 could be parked on it and hit with a simulated nuclear pulse. It was shut down at the end of the Cold War, and it is still there.
In the Nevada desert the US government built two small American towns, filled them with furniture, food and dressed mannequins, and then dropped atomic bombs on them to show what would happen to a family at home. One was destroyed in 1953. Part of the other still stands.
Bakić's 37-metre monument to the 1941 uprising once glittered with Swedish stainless steel above the forests of central Croatia. Now it is stripped, graffitied and carrying phone antennas, and a Netflix crew has filmed in it.
In December 1943 the 150 people of Imber were told to leave their Wiltshire village for a few months so American troops could train there. They never came back, and the village still stands empty inside an army firing range.
Kadykchan in Russia's far north-east was dug out of the permafrost by Gulag prisoners in 1943 to feed a power station. Then a mine explosion and a state decision left its flats empty and its streets silent.
Prora was meant to be a seaside holiday camp for 20,000 workers, a block of concrete 4.5 kilometres long on Rügen's Baltic coast. The war stopped it before a single holidaymaker arrived, and the shell went on to serve three armies before the luxury flats moved in.
In 1997 a 45-metre Gulliver was laid out on a hillside below Mount Fuji, tied down by Lilliputians, and four years later the park was dead. The bank behind it had collapsed, and the giant stayed where he lay for six more years.
Okunoshima is famous for the hundreds of rabbits that greet every ferry, but from 1929 to 1945 it was a secret island where the Imperial Japanese Army made thousands of tons of poison gas.
Hidden in the Brandenburg forest north of Berlin, Vogelsang was a Soviet garrison town of up to 15,000 people, and for a few months in 1959 it held the first Soviet nuclear missiles in Germany.
Beneath Moscow there is said to be a second, secret metro for the country's leaders. Parts of the story are documented, and the rest is rumour that nobody in power will confirm.
Hidden in a Crimean mountain under 180 metres of rock, Object 221 was meant to run the Soviet Black Sea Fleet through a nuclear war. It was never finished, then looted, and now it may be back in military hands.
Hundreds of metres below a small town in eastern Ukraine lay one of Europe's largest salt mines, with a church, a concert hall and a football pitch carved from salt. Then the war reached it.
Cut into a mountain beside a narrow Crimean bay, Balaklava's secret submarine base was built to survive a nuclear strike and is now a museum.
Along France's Atlantic coast, Germany built vast concrete bunkers for its U-boats during the Second World War. Bombers could not break them, and today they are museums, art galleries, naval stores and silent ruins.
On the cliffs near Cap Gris-Nez, four huge concrete casemates once held German naval guns that could hit the English coast. One of them is now a museum, and the rest still stand in the fields.
Built in the Second World War with a runway half as long again as normal, RAF Sculthorpe became one of the biggest US Air Force bases in Britain, home to nuclear-capable bombers until it closed in 1992.
High in the Swiss Alps, a laboratory cut into the rock of the Jungfraujoch has measured cosmic rays, glaciers and the air since the 1930s.
Above Svalbard's Isfjorden, the ruins of Grumant mark a Russian and Soviet coal town that was evacuated in the war, shelled, rebuilt, and abandoned for good in the 1960s.
