Historically, Buddhism was incorporated into Russian lands in the early 17th century, when Kalmyk people traveled to and settled in Siberia and what is now the Russian Far East. Buddhism is considered as one of Russia’s traditional religions, legally a part of Russian historical heritage. The main form of Buddhism in Russia is Tibetan Buddhism. Although Tibetan Buddhism is most often associated with Tibet, it spread into Mongolia, and via Mongolia into Russia. It spread into the Russian constituent regions geographically and /or culturally adjacent to Mongolia: Buryatia, Zabaykalsky Krai, Tuva Republic, and Kalmykia, the latter being the only Buddhist region in Europe, located to the north of the Caucasus. By 1887, there were already 29 publishing houses and numerous datsans. After the Russian Revolution, the datsans were closed down. By the 1930s, Buddhists were suffering more than any other religious community in the Soviet Union with lamas being expelled and accused of being "Japanese spies" and "the people's enemies". After the fall of the Soviet Union, a Buddhist revival began in Kalmykia with the election of President Kirsan Ilyumzhinov. Today, Tibetan Buddhism is primarily practiced by the indigenous peoples in these regions of central and eastern Russia, except for a few Russian converts based mainly in the larger cities as St. Petersburg and Moscow, where there is greater access to urban Buddhist centers or facilities of the like. The other major forms of Buddhism found in Russia are traditions practiced by immigrant communities, among them the Koreans, Chinese, Vietnamese, and others, based mainly in the large cities. In 1979, the Dalai Lama made his first visit to Russia. There are several Tibetan Buddhist university-monasteries throughout Russia, concentrated in Siberia, known as Datsans.