Moscow is one of the largest science centers in Russia. The headquarters of the Russian Academy of Sciences are located in Moscow as well as research and applied science institutions. The Kurchatov Institute, Russia's leading research and development institution in the fields of nuclear energy, where the first nuclear reactor in Europe was built, the Landau Institute for Theoretical Physics, Institute for Theoretical and Experimental Physics, Kapitza Institute for Physical Problems and Steklov Institute of Mathematics are all situated in Moscow.