By some reckonings, the Cold War began in 1945 at Trinity Site, New Mexico, with the explosion of the first atomic bomb, and ended 41 years later at Chernobyl, where the meltdown of a nuclear reactor became a precipitating event of the Soviet Union's downfall. (Read more in National Geographic magazine: "The Nuclear Tourist: An unforeseen legacy of the Chernobyl meltdown.")
Today some of the era's historic sites are open to visitors—a reminder of a time when two great powers were continuously on alert to wage nuclear war. Here are some of the key locations:
1. A Chain Reaction Starts in Chicago
On Ellis Avenue at the University of Chicago, a bronze Henry Moore sculpture marks the site of Chicago Pile 1. It was here in 1942, the early days of the Manhattan Project, that Enrico Fermi and his team ignited the first self-sustaining nuclear chain reaction. The following year, the reactor's graphite blocks were dismantled and reassembled for more experiments at a site in the Palos Forest Preserve, southwest of Chicago. In the mid-1950s it was decommissioned, and the remains, along with those of another reactor, were buried and marked with a stone monument—the world's first nuclear ruins.
2. A Bomb Is Born in New Mexico
From Chicago, the research moved to the cool mountain air of Los Alamos, New Mexico, where the first atomic bomb was made. (Manhattan, the new TV series, has it wrong: This is not a desert.) A walking tour takes you by Fuller Lodge, the majestic log structure that served as a dining and meeting hall for the project, which occupied the site of a former boys' school. The guest cabin next to the lodge now houses the Los Alamos Historical Museum, and nearby are the homes of Bathtub Row, the comparatively luxurious residences where Robert Oppenheimer, Hans Bethe, and other luminaries lived. The old laboratory sites are still hidden within the pine forests of the fenced restricted area. But the Atomic Heritage Foundation is lobbying Congress to incorporate them into a National Historical Park. It would also include other Manhattan Project facilities like those in Hanford, Washington, and Oak Ridge, Tennessee.
3. The Atomic Era Triggered at Trinity Site
About 200 miles south of Los Alamos, in an area called Jornada del Muerto, or "journey of the dead," is Trinity Site. This really is a desert, and it was here on July 16, 1945, that the first atomic bomb—the Gadget—was exploded. Once a year, on the first Saturday in April, the site is open to tourists. The steel tower supporting the bomb was vaporized in the blast, and the crater was later filled and marked by an obelisk. The heat of the explosion fused sand and other debris into green glassy rocks called Trinitite. You're not allowed to take whatever pieces remain, though they often show up for sale on eBay.
4. Cities in Japan Recall Nuclear Devastation
The bombs had been meant for Hitler, but with the defeat of Germany the target became Japan. The two cities that were bombed, Hiroshima and Nagasaki, have built parks and monuments, near ground zero, in remembrance of the horror. The most striking site at the Hiroshima Peace Memorial Park is the wreckage of the Industrial Promotion Hall, now called the A-Bomb Dome. At the Nagasaki Peace Park, a masonry wall stands as a reminder of the original Urakami Cathedral, where parishioners were worshipping when the bomb fell.
5. Bikini Atoll Becomes a Test Site
Less than a year after Japan's surrender came the first nuclear tests at Bikini Atoll in the remote Marshall Islands—remote, except to the inhabitants, who were relocated to nearby islands as a fleet of surplus ships, some captured from Japan and Germany, arrived. For the next few years the vessels served as targets for atomic bombs. The last and largest, in 1954, was a 15-megaton thermonuclear device—far more powerful than the scientists had reckoned—that spread radioactive fallout some Marshall Islanders mistook for snow. In the late 1970s a mammoth attempt to clean up and resettle the atoll ended in failure. Today it is a destination for divers, who can explore the sunken wreckage and lament the Bikinians' fate.
6. Nevada Desert Becomes a Testing Ground
From 1951 until the Limited Test Ban Treaty of 1963, more than a hundred nuclear weapons were detonated in the desert air of the Nevada Test Site. Afterward underground blasts continued there for 30 more years. Today the Department of Energy schedules monthly tours, which depart from the Atomic Testing Museum in Las Vegas and visit sites including the Sedan Crater (1,280 feet in diameter and 320 feet deep), part of the Plowshare Program to see if nuclear explosions could be used for mining and for excavating canals, roadcuts, and quarries. Another stop is Survival Town, site of the remains of buildings erected and populated with mannequins—nuclear crash-test dummies—and then rocked with atomic blasts.
7. Missile Silos Stay on Alert in Arizona
Throughout the Cold War, intercontinental ballistic missiles sat in their silos as crew members waited around the clock for orders to launch an attack on the Soviet Union. The legendary Titan II was capable of delivering a nine-megaton warhead at a speed of 15,000 miles an hour to targets across the ocean. Today at the Titan Missile Museum near Tucson, visitors can descend into a decommissioned silo and even arrange to spend the night. "What was it like for Titan II crew members to sleep underground only a few feet away from the largest missile ever made by the United States? Now you can find out!"
8. Bunkers Await U.S. Leaders in Virginia, West Virginia
Had there been a nuclear war with the Soviet Union, the president of the United States and other officials might have waited out the fallout in a vast bunker inside Mount Weather, Virginia. Congress, meanwhile, would have relocated to another underground facility at Greenbrier resort in the mountains of West Virginia, where chambers had been excavated for the House and Senate. Mount Weather, still in operation, is closed to the public, but the Greenbrier resort offers tours of the former retreat. After emerging from the cavernous hideout, guests of the hotel can enjoy a game of golf and then head for the casino, perhaps to contemplate the deadly gamble that was the nuclear arms race.