A kremlin is a major fortified central complex found in historic Russian cities. The word is often used to refer to the Moscow Kremlin and - metonymically - to the government based there. Other such fortresses are called detinets, such as the Novgorod Detinets.

The Moscow Kremlin, or simply the Kremlin, is a fortified complex in Moscow, Russia. Located in the centre of the country's capital city, it is the best known of the kremlins and includes five palaces, four cathedrals, and the enclosing Kremlin Wall along with the Kremlin towers. Within the complex is the Grand Kremlin Palace, which served as the royal residence of the Emperor of Russia. It is now the official residence of the President of the Russian Federation. The Kremlin overlooks the Moskva River to the south, Saint Basil's Cathedral and Red Square to the east, and Alexander Garden to the west.