Yekaterinburg, alternatively romanized as Ekaterinburg and formerly known as Sverdlovsk (1924–1991), is a city and the administrative centre of Sverdlovsk Oblast and the Ural Federal District, Russia. The city is located on the Iset River between the Volga-Ural region and Siberia, with a population of roughly 1.5 million residents, up to 2.2 million residents in the urban agglomeration. Yekaterinburg is the fourth most populous city in Russia, the largest city in the Ural Federal District, and one of Russia's main cultural and industrial centres. Yekaterinburg has been dubbed the "third capital of Russia", as it is ranked third by the size of its economy, culture, transportation and tourism, behind Moscow and Saint Petersburg.