Hadron Collider, Russia

Orthodox Christianity, Islam, Buddhism and Judaism are Russia’s traditional religions, legally a part of Russia's "historical heritage". Estimates of believers widely fluctuate among sources, and some reports put the number of non-believers in Russia at 16–48% of the population.
Easter is the most popular religious festival in Russia, celebrated by more than 90% of all Russian citizens, including large number of non-religious. More than three-fourth of the Russians celebrate Easter by making traditional Easter cakes, coloured eggs and paskha.
Traced back to the Christianization of Kievan Rus' in the 10th century, Russian Orthodoxy is the dominant religion in the country; approximately 100 million citizens consider themselves Russian Orthodox Christians. 95% of the registered Orthodox parishes belong to the Russian Orthodox Church while there are a number of smaller Orthodox Churches. However, the vast majority of Orthodox believers do not attend church on a regular basis. Smaller Christian denominations such as Catholics, Armenian Gregorians, and various Protestants exist.
Estimates of the number of Muslims in Russia range from 7–9 million by the local sources to 15–20 million by Western and Islamic sources. Also there are 3 to 4 million temporary Muslim migrants from the post-Soviet states. Most Muslims live in the Volga-Ural region, as well as in the Caucasus, Moscow, St. Petersburg and Western Siberia.