Nizhny Novgorod is the administrative centre of Nizhny Novgorod Oblast and the Volga Federal District in Russia. The city is located at the confluence of the Oka and the Volga rivers in Central Russia, with a population of over 1.2 million residents, up to roughly 1.7 million residents in the urban agglomeration. Nizhny Novgorod is the sixth-largest city in Russia, the second-most populous city on the Volga, as well as the Volga Federal District. It is an important economic, transportation, scientific, educational and cultural centre in Russia and the vast Volga-Vyatka economic region, and is the main centre of river tourism in Russia. In the historic part of the city there are many universities, theatres, museums and churches.