Kaluga (Russian: Калу́га) is a city in central Russia, located on the Oka River 188 km southwest of Moscow. It is the administrative center of Kaluga Oblast. Kaluga was founded in the mid-14th century as a border fortress on the southwestern borders of the Muscovy. It was first mentioned by its present name in 1371. In the Middle Ages, Kaluga was a minor settlement owned by the Princes Vorotynsky. The ancestral home of these princes is located south-west from the modern city. Kaluga is connected to Moscow by a railway line and the ancient roadway (E105 International highway) which is known as the Kaluga road. This road was the favoured escape route from the Moscow trap for Napoleon in the fall of 1812. But General Kutuzov repelled Napoleon's advances in this direction and forced the retreating French army onto the old Smolensk road, previously devastated by the French during their invasion of Russia. Kaluga was occupied by the Nazi armies in 1941. Kaluga is known for its most famous resident, Konstantin Tsiolkovsky, a rocket science pioneer who worked here as a school teacher. There is a museum in Kaluga dedicated to his theoretical achievements and their practical implementations for modern space research, hence the motto on the city's coat of arms: "The Cradle of Space Exploration".