Revelers in the English university city of Oxford took part in the annual May Morning festival on Monday - an event famous for its centuries-old cultural traditions, as well as some rowdier modern ones.
The festival features traditional music and dancing and frequently attracts crowds in the tens of thousands.
The ceremony that begins the festival, featuring the choir from Magdalen College performing "Hymnus Eucharisticus" goes back some 500 years, the college says.
Following the performance, which sees choristers sing from atop a church tower, bells ring out across the city of for 20 minutes and then festivities, including traditional Morris dancing, begin across the city.
The event has attracted unwelcome attention in recent decades, as revelers, often fueled by alcohol, pushed to take part in a comparatively new tradition of leaping into the Cherwell river from the city's Magdalen Bridge.
After 40 people were injured jumping into the river in 2005, local authorities installed crash barriers and hired security guards to prevent people jumping from the bridge.
Despite the forced end of bridge-jumping, the event still maintains a party spirit.