Self-styled Druids, new-agers and thousands of revellers have watched the sun rise above the ancient stone circle at Stonehenge to mark the summer solstice the longest day of the year in the northern hemisphere.

English Heritage, which manages the monument, says some 36,000 sun-watchers gathered on the Salisbury Plain about 80 miles (130 kilometres) southwest of London on Saturday. Police say the event was peaceful with only 25 arrests, mainly for drug offences.

Couples kissed, dancers circled with hoops and revellers took part in a mass yoga practice as part of the free-form celebrations.

Stonehenge was built in three phases between 3000 B.C. and 1600 B.C. and its purpose remains under study. An icon of Britain, it remains one of its most popular tourist attractions.