Cardiff Bay landmarks have been fenced off and police have stepped up patrols in parts of Wales in a bid to stop crowds breaking Covid rules.
Special powers remain in place allowing officers to move people away in the bay area after hundreds gathered on the Senedd steps in recent days.
The area around the Welsh Parliament has also been cordoned off.
Across Wales police stepped up patrols after large groups were seen drinking on beaches and at beauty spots.
Supt Marc Attwell, of South Wales Police, said people needed to take "personal responsibility" to prevent a third wave following the scenes in Cardiff Bay on Friday night.
Meanwhile, Cardiff council has urged people to remember "the pandemic is not over" after crowds gathered in various areas over the Easter weekend leaving piles of rubbish behind.
Current Covid rules state six people from two different households can meet outdoors in Wales, but mass gatherings remain illegal.
But, in recent days communities and authorities across Wales have faced major clean-up operations, after groups gathered to enjoy the sunshine.
In Cardiff Bay barriers have been placed around the Senedd after hundreds of people congregated on Thursday and Friday, leading to arrests.
A dispersal order remains in place in the area around the Welsh Parliament, meaning police can remove people from the vicinity, after gatherings saw police injured and the area left covered with litter.
Security fencing has also been placed around a memorial to merchant seamen, after people were reportedly seen urinating on it.
The council said large groups of people "intent on breaking Covid-19 restrictions" had left substantial amounts of litter in the area on Friday, and bins it had put in place had not been used.
"Breaking these rules significantly increases the chances of Covid-19 cases rising in the city," a spokesperson said.
In the Bodlondeb area of Conwy, police have been given powers to move people on until Sunday night, after reports of "groups of youths gathering and causing anti-social behaviour".
What is a dispersal order?
- A dispersal order can be imposed on a specific area for up to 48 hours under section 35 of the Anti-social Behaviour, Crime and Policing Act 2014
- The order gives police and community support officers the power to require people to leave a particular area and not return for a period of time
- It aims to prevent disorder and "members of the public in the locality being harassed, alarmed or distressed"
- Failure to follow the order could leave people with a fine or up to three months in jail
- Source: UK government website
Meanwhile in Swansea volunteers spent hours cleaning beaches of bottles, litter and smashed glass, while the council put out warnings after "high" levels of rubbish were left at beauty spots.
At Aberavon, in Neath Port Talbot, police spent Saturday evening patrolling the sand dunes after groups drank on the beach and started bonfires.
Meanwhile in north Wales, firefighters issued warnings after a grass fire in Dolgellau on Saturday, urging people not to set deliberate fires or burn waste.