At the very heart of the beast that was the Soviet Union stands the fortified complex known as the Kremlin. Separated from Moscow's iconic Red Square by thick impenetrable walls, the Kremlin was for Centuries the official residence of the Russian Tsars. * And this fine tradition continues to this day, as the Kremlin is the home of Vladimir Putin, President of the Russian Federation. He lives in the Kremlin Senate building, which is obviously the most secure part of the fortress.