The first full-scale reactor on Earth, critical in September 1944
At the Hanford Site near Richland stands the first large-scale nuclear reactor ever built, 250 megawatts, which went critical on 26 September 1944. Its job was to turn part of its natural uranium fuel into plutonium-239 by neutron activation, and that plutonium was chemically separated for weapons. This is where the material for the Nagasaki bomb was made, and the building is preserved because of it, not in spite of it.
Other places on the map within a couple of hours of here.
