Drivers have been fined almost 150 times since parking charges were brought in at Cosmeston Lakes Country Park.
Parking charges were introduced at the popular park, south of Penarth, in July.
Several visitors have complained there aren’t clear enough signs warning drivers of the new charges, and others have said the parking machines often have long queues.
New data revealed by a freedom of information request shows drivers at Cosmeston have been fined far more often than nearby car parks over the past eight weeks.
Vale of Glamorgan council brought in parking charges at Cosmeston, and also at Porthkerry Country Park near Barry, on July 19. Council bosses said visitors should help pay for the upkeep of country parks.
Since July 19, the council has issued 146 penalty charge notices at Cosmeston, according to the freedom of information request.
This is far more than nearby public car parks. In the same time period, Nells Point saw 74 fines issued, Rivermouth 17 fines, Harbour Road 34 fines, Southerndown three fines, and Brig Y Don nine fines.
No fines have been issued to drivers at Porthkerry since the charges were brought in, due to “device errors”.
Dr Sumanta Barua, who sent the freedom of information request, said: “There is a lack of clear signs throughout the Cosmeston car park, and regular visitors like us are caught by surprise.
“The car park charges are relatively cheap, so why would so many people take the risk, especially those like me who have never had to pay fines before? The day I got fined, I was not the only one.”
Responding to the concerns, the council said the fines made up a very small portion of the number of drivers who have paid to park at Cosmeston since the charges were introduced.
Councillor Peter King, cabinet member for neighbourhood services and transport, said: “The number of penalty notices issued represents less than 0.5 per cent of the number of vehicles that have paid to park at Cosmeston since July 19.
“This suggests that the vast majority of people are happy to pay for parking, particularly as it will contribute to future investment in our country parks.”