The SNR-300 was a fast breeder sodium-cooled nuclear reactor built near the town of Kalkar, North Rhine-Westphalia, Germany.[1] The reactor was completed but never taken online. SNR-300 was to output 327 megawatts. The project cost about 7 billion Deutsche Mark (about €3.5 billion or over $4 billion). The site is now the location of a theme park, Wunderland Kalkar, which incorporates much of the power plant buildings into the scenery.