More than a mile of seafront has been shut by police to prevent thousands gathering for an illegal rave.
Police got wind of a planned event in Chalkwell in Essex.
A dispersal order has been put in place banning large groups from gathering.
Ravers had been plotting the huge event on one of the hottest nights of the summer today.
But it comes as new lockdown measures are introduced in parts of England to stop a new tide of coronavirus infections.
The order will be in place from 7pm this evening to 4am tomorrow morning, Essex Live reports.
A statement from Essex Police said: "A dispersal order will be in place covering Chalkwell Park, following information about a large planned gathering.
"It will be in place from 7pm on Friday 31 July to 4am Saturday 1 August.
"The order will cover the area shown in the map below, including London Road, Chalkwell Avenue, Leigh Road, Mount Avenue and Chalkwell Esplanade and the beach to the low water marker.
"The order has been put in place to reduce the likelihood of anti-social behaviour and to prevent any crime and disorder that might be associated with the event.
"Anyone who witnesses any incidents is asked to call 101. Please call 999 in an emergency."
Today thousands packed onto beaches across the UK as temperatures soared.
Pictures show large crowds gathered at nearby Southend beach.
