Naadam is a traditional type of festival in Mongolia. The festival is also locally termed "eriin gurvan naadam" - "the three games of men". The games are Mongolian wrestling, horse racing and archery and are held throughout the country during the midsummer holidays.
In 1989 when communism was starting to fall elsewhere, many Mongolian weren't really ready for the change.
Traditionally, Mongols practiced Shamanism, worshipping the Blue Sky. However, Tibetan Buddhism (also called Vajrayana Buddhism) gained more popularity after it was introduced in 16th century.