Like North Korea, the U.S. has a history of conducting its own nuclear tests. The first successful atom bomb test happened in Alamogordo, New Mexico, on July 16, 1945. It was code named “Trinity.” That detonation was a part of the Manhattan Project, a government research project during World War II that gave us the first nuclear weapons. Near the end of World War II, on August 6, 1945, the United States dropped an atomic bomb over the Japanese city of Hiroshima, and three days later another bomb over Nagasaki. Those were the first and last times nuclear weapons have been used in combat.

But since then more than 2,000 nuclear tests have been conducted in more than half-a-dozen countries. There have been a few treaties against testing put in place. A Partial Test Ban Treaty was signed in 1963 to prevent test detonations in the atmosphere, in space, and underwater. And in 1996 the Comprehensive Nuclear-Test-Ban Treaty was adopted to ban all nuclear explosions — but it has not been enforced. In 2009 the United Nations General Assembly declared Aug. 29 to be an International Day Against Nuclear Tests.

Of the eight countries that have tested nuclear weapons, only one has done so after 1998: North Korea. The country’s most recent test, a hydrogen bomb, occurred in September 2016. The U.S. currently relies on experimental data from computer models instead of testing live bombs.

The gallery above shows a selection of nuclear tests conducted between 1945 and present day.