Around 25,000 people were estimated to have visited Barry Island in one day this week, according to police.
South Wales Police shared a pictured of the packed beach in the Vale of Glamorgan on Thursday.
The neighbourhood policing team officers said they dealt with “several missing children, persons with alcohol, found property and drug offences.”
It comes after police reported “outbreaks of disorder” at Barry Island on July 22.
The Vale of Glamorgan Deputy Council Leader Lis Burnett told BBC Radio Wales the council is working closely with the police to ensure popular beach destinations such as Barry Island remain “just a nice family day out”.
She said: “I think that a lot of people have seen a range of incidents that are happening at coastal locations, right across Wales actually, nothing on the scale that we have seen in some of the places in London but it is still a major inconvenience to people that are trying to use resort destinations in a responsible way.”
Ms Burnett added that the council is considering introducing Public Space Protection Orders (PSPO) that would ban drinking in certain areas.
“So we have had these what are called PSPOs, public space protection orders, in a lot of areas in the Vale over the years,” said Ms Burnett.
“We don’t always use them because they are completely associated with antisocial behaviour, but we want measures available to us that both we and the police working together can enforce to make sure that we can clamp down on antisocial behaviour and mass gatherings.”
“Yesterday I think the estimates were 20 to 25,000 on Barry Island so we need to make sure it stays a nice place to go for families, because at the end of the day it is a family destination.
“Sometimes fights will kick off. But we all know that we want our destinations on the coast in Wales to be nice family destinations and sometimes you need these sorts of things to allow you to remind people of how they should be behaving.
“We are not talking ‘come to Barry Island and you are going to get searched by the police’, this is about ‘let’s keep things looking nice’.”
On Friday social media users complained that trains heading towards Barry Island were “heaving” as Wales Online reported three miles of tailbacks towards the beach.
“Trains to Barry Island are a joke!!!!!” said one social media user on Twitter.
“They are heaving. People are obviously going to the island, you should stop them or send trains only to Cadoxton and then Rhoose!!”
Leyton Powell, Safety and Assurance Director, Transport for Wales Rail Services said: “The safety of customers and colleagues is our top priority and we’re asking everyone to only use public transport for essential travel and where there are no other travel alternatives.
“Our capacity has been massively reduced due to social distancing measures and we must maintain safe space for those key workers using our services.”
The Welsh First Minister Mark Drakeford announced on Friday that coronavirus lockdown restrictions would be eased further in Wales.
Up to 30 people can meet outside in Wales while maintaining social distancing from Monday.
Mr Drakeford said that the changes would “help make life easier for family and friends” but would be restricted to outside locations “because we know it’s much safer to be meeting in the outdoors and the sunlight”.