Chernobyl, Pripryat Ukraine. This is Reactor 4, THE reactor that caught fire and caused the nuclear accident which made Chernobyl a household name, and ultimately caused the fall of the Berlin Wall. It sits on the Pripryat River, which was used to cool the core. It is one of six reactors all close together. The Chernobyl Nuclear Power Plant is in the north of Ukraine, very near the border with Belarus. Chernobyl itself was overtaken in size and importance by the new Atomic City of Pripryat, just a couple of Kilomteres from this reactor.