The Kremlin is the oldest part of Moscow, Russia's capital. It sits on the high left bank of the Moscow River with Red Square located to its east. The Kremlin and Red Square together form the capital's main political, religious, historical and architectural ensemble. The Kremlin has always been the symbol of the capital. At first it was made of wood, and after numerous fires, of stone and finally of bricks. Russian sovereigns and spiritual leaders lived within its walls for centuries. The Kremlin now serves as the main working and ceremonial residence of the President of the Russian Federation.