The great Stupa of Boudinath towers over the district of Chabahil and remains one of the great Newari trading centres with Tibet. The ancient stupa is a major pilgrimage site for Buddhists, one of the most important holy places in Nepal and is also the largest Tibetan settlement outside Tibet. The massive white dome dates back to AD 600. You can climb up onto its base and sit and look out at the mountains or the devout doing kora, walking round the stupa praying. Their chants are an ever-present murmur in the background of life in Boudha. As with most Buddhist structures, the stupa's base is shaped like a mandala, a symbol of the universe that serves as an aid to meditation. The five elements appear in its design. The base, earth; the dome, water; the central tower, fire; the umbrella, air; the pinnacle on top, ether. There are 13 rings from the base to the pinnacle, symbolizing the steps to enlightenment, or Bodhi, hence the stupa's name. There are 147 niches around the outer wall; each one houses four or five prayer wheels. There are also 108 forms of Buddha sculpted into the base.