The great Stupa of Boudhanath, the largest in Nepal, the Holiest outside of Tibet, stands approximately six kilometers east of the center of the Kathmandu Valley. Built around the 14th century, it hosts the largest celebration in Nepal during the Festival of Losar (Tibetan New Year) in February or March. It is, on the Indian sub-continent, a major destination for pilgrims from the Himalayas, Tibet, South and Eastern Asia. It is also one of three largest and most significant Buddhist monuments in the world and a UNESCO World Heritage Site. A must to visit when in Nepal.