St. Petersburg, recently celebrated its tercentenary, often called the "Northern Capital" of Russia - is not only an open-air museum, but also reflection of the last three hundred years of Russian history. Having been survived 11 Emperors, dozens of floods, the revolution, three years of terrible blockade and economic reform, Saint-Petersburg is able to surprise even the most experienced and capricious tourists.On 27 May 1703, the day of the Holy Trinity, the fortress "St. Peterburgh” was founded. This day is considered to be the day of foundation of St. Petersburg. The city was named in honor of the Apostle St. Peter, who is considered to be the keeper of the keys to paradise, according to the Christian tradition. And it is believed that Peter is one of the patrons of the city, protecting it from the troubles and disasters. Only a few years later the fortress was renamed in the Peter and Paul Fortress - under the name of its main cathedral.Among the largest cities in Europe St. Petersburg is one of the youngest. The houses were built of stone, and the buildings, that had been erected before 1917, are almost entirely preserved. There are about 18 thousands old buildings in the city. The territory of the city from Obvodny channel to the Neva River and from the Alexander Nevsky Monastery to the port looks almost the same as before 1917. There is no city in Europe or America where You could find so many preserved old buildings. Moreover, St.Petersburg is the only city in the world, where you can see the buildings of different architectural styles such as Classicism, Eclecticism and Art Nouveau.Since the middle of the XVIII century and until now St. Petersburg is the fourth most populated city in Europe. The championship has been always held by London and Paris, but between Naples, Vienna, Berlin and Moscow there was a struggle for European bronze. St. Petersburg reached its maximal population in 1990: 5,2 million people. Now the city continues to hold its traditional fourth place after Moscow, London and Paris.Russian Orthodoxy is the main religion in St. Petersburg (there are about 91% of the faithful people), but there are also followers of other religions, including Muslims (5%), Catholics (1%) and Jews (1%). Also, there are groups of Buddhists, Seventh-Day Adventists, representatives of the Salvation Army, Pentecostals, Jehovah's Witnesses, Mormons.The churches and Cathedrals of St. Petersburg form an integral part of the architectural and cultural landscape of the city. Saint-Petersburg is a city of different nationalities and religions, where churches are open for different confessions. They give a special charm to the city landscape - sometimes exotic, sometimes classical silhouettes of mosques, churches, synagogues emphasize multinational character of the city.St. Petersburgis is included in the UNESCO World Heritage List as an important center of tourism in Russia.