Fri Jun 21, 6:57 AM ET By Jason Hopps and Pete Harrison STONEHENGE, ENGLAND (Reuters) - Chanting and dancing to whistles and drums, thousands of revellers and a handful of robed Druids welcomed the summer solstice on Friday in one of the biggest-ever gatherings at the ancient Stonehenge megalith. While most of bleary-eyed England was rising early to watch a crunch World Cup football match, more than 16,000 people thronged to Salisbury Plain in Wiltshire, southern England, to greet the longest day of the year. "It is fantastic to come here at a non-corporate public monument and celebrate with so much energy when the sun is at its highest point," said Jane Parker, 37, holding two flaming juggling clubs at her side. The celebrations began Thursday night when a rainbow assortment of spiritualists, Druids and dreadlocked mothers pushing prams descended on the site for a once-a-year chance to walk among its towering stones. As dawn broke above one of the stone archways, Druids -- a pagan religious order dating to Celtic Britain -- joined with the crowds in chants and cheers of joy. But the atmosphere was filled more with cannabis then incantation. "I think most of the people here are on a spiritual quest and even those who aren't can find wisdom here," said Brian "Earthspoon," an unofficial spokesman for the celebration. English Heritage, guardians of Stonehenge, a world heritage site, estimated the crowd numbers at 16,000, by far the largest gathering since it reopened the stone circle for the solstice festival in 2000. It was only the third time since violence marred the event in 1985 that English Heritage allowed the public among the stones inside the site, about 80 miles southwest of London. The banning of the Stonehenge Free Festival, an annual day of public access to the stones, sparked clashes in 1985 between riot police and visitors who had made spiritual pilgrimages to the site demanding to be allowed to perform religious rites. Since then, access to Stonehenge -- built between 3,000 B.C. and 1600 B.C. -- has been limited, but the solstice attracts thousands every year. Theories abound about the purpose of the stunning stone circle. Historians are undecided as to whether it was built as a temple, a burial ground, a calendar or if it served a variety of religious and temporal purposes. Regardless, the site is one of Britain's most popular tourist attractions, receiving about one million visitors annually. Even England's hotly-anticipated World Cup quarter-final clash against Brazil wasn't enough to tempt the truly faithful away from the standing stones. "I'd love to watch the game, but being here is far more important," said Earthspoon.