The history of the Russian Federation is overwhelming. It is apparent on every corner of the country's staggeringly awesome cities, such as Moscow and St Petersburg, with their architectural marvels. But it also dwells in huge and remote expanses such as Siberia, filled with ancient forests and the world's deepest lake. Russia is one of the most complex countries of the world and yet it is precisely because complexity that it remains so endlessly fascinating. And it is in spite of it that it retains the simple truth of being so aesthetically beautiful. Cities As of 2005 Russia has 13 cities with over a million inhabitants (from largest to smallest): Moscow, Saint Petersburg, Novosibirsk, Yekaterinburg, Nizhny Novgorod, Samara, Omsk, Kazan, Chelyabinsk, Rostov-on-Don, Ufa, Volgograd and Perm. Tourism in Russia has been growing rapidly in the years following the collapse of the former Soviet Union in 1991. Most of the tourism is centered on the cities of Moscow and St. Petersburg, since these cities are the sites of some of the most famous attractions of Russia. Tourists are attracted by the very rich cultural heritage and rather tumultuous history of Russia, and this is reflected in the popularity of Russia's most famous attractions