On this day in 1945, in the American southwest, the first atomic bomb detonated. It changed the world forever.
Now, there are more than 17,000
And with 68 years since the bombs were dropped on Hiroshima and Nagasaki, most of the world's population has never seen a nuclear weapon attack.
But there's a site that allows anyone to see the effects of a nuclear weapon anywhere in the world.
NUKEMAP, created by Alex Wellerstein, a nuclear historian, allows people to explore the blast radius of a nuclear bomb anywhere in the world. Users can select the tiniest bomb ever designed, all the way up to the largest, and see what the fall out would be.
"Just as the atomic bomb has been treated as something above and beyond any other category of warfare," Wellerstein writes in the blog, "so has its secrecy."