Swimmers taking a dip in London's historic Hampstead Ponds will now have to pay for the privilege after authorities introduced a fee.
People have been bathing in the ponds since the 1850s
The Hampstead Heath Management Committee has brought in a fee of £2 a day to use the three pools, used by swimmers since the 1850s.
The fee will be a "self-policing system" - while regular users will be able to buy a season ticket.
But swimmers are angry at the charge, saying the scheme is "out of order".
The Corporation of London, which manages Hampstead Heath, says the three ponds cost more than £500,000 a year to maintain, and each pond requires at least two full-time lifeguards to protect swimmers.
The corporation believes the self-policing charge - as well as new parking fees - will bring an extra £130,000 a year but they said they had considered closing the ponds to the public.
The plans to charge money for swims have brought an angry response.
Elizabeth Block, of the Kenwood Ladies Pond Association, said: "Swimmers are very angry because they believe there's a long tradition of free swimming, and we want that maintained."
But the Corporation of London does not agree, saying the charge would protect other facilities on the Heath.
"A modest self-policing charge, £2 a visit, is perfectly reasonable thing to ask people to pay," said the corporation's Tony Halmos.
"Within the budget constraint any organisation has... you have to look at the balance between other facilities and other services and see if a modest charge would offset other costs," he said.
The Heath car parks will now also charge a fee - a pay-and-display scheme to deter commuters and non-Heath users from parking all day, the corporation said.