The Russian metropolis of Kazan, home to over a million residents, is an important centre for mechanical engineering and functions as a traffic hub on the Volga. The city was founded at the beginning of the 11th century, probably by Volga Bulgars. Kazan is the Tatar cultural centre and visitors can learn about this culture in the State Museum of the Tatar State and the Republic of Tatarstan. In addition, Kazan is the centre of Islam in Russia. The colourful towers and churches of the 16th century Kremlin are among the city's landmarks. Kazan's climate is moderately continental with cold winters and mild summers. To the south of Kazan is Samara, another important metropolis in the Volga region, known for its kilometre long river promenade.