Police at a Merseyside beauty spot had to turn cars back from as far as away as Leeds and Manchester at the weekend.
Officers at Formby beach turned away more than 100 cars and issued 20 people with fines for breaching Covid-19 rules on Saturday, Merseyside Police said.
Supt Graeme Robson said travelling from West Yorkshire and Greater Manchester was "totally unacceptable" and showed a "complete disregard" for the guidance.
MP for Sefton Central, Bill Esterson, called their actions "reckless".
Supt Robson said the good weather at the weekend had seen a "large increase in people travelling to the Formby beach area, some of whom had travelled a significant distance to get there".
"Individuals from as far as Leeds, Manchester and Stockport were found which is quite frankly astounding," he said.
"Now more than ever people should be taking heed of the advice, so that infection rates can continue to drop, and we can meet the criteria necessary for easing lockdown in the upcoming weeks and months."
One local woman said she was trapped in her home because "there were cars double parked right the way down the street".
"As I have a baby it meant we couldn't go out whatsoever on Saturday or Sunday," she told the Local Democracy Reporting Service.
"I get that other people want to, and should be able to, visit the beach, I just wish people wouldn't be so selfish when it comes to parking."
Mr Esterson said those travelling from outside the region were "deeply irresponsible".
"While it may be tempting to leave your area for travel and leisure, people should be acting responsibly so that infection rates continue to drop," he added.
"We are so close to the finish line, as Sefton's cases edge closer to dropping below 100 cases per 100,000. Let's not ruin it now."
New data has revealed nearly 70,000 fines have been given to people in England and Wales for breaching coronavirus lockdown rules.
National Police Chiefs' Council (NPCC) figures show 68,952 fines were issued between 27 March 2020 and 14 February 2021.