A conservation group is objecting to plans by the London 2012 Olympic organisers to build viewing structures in an area of Weymouth, Dorset.
The London 2012 Organising Committee (Locog) wants to construct "temporary structures" at Nothe Gardens to enable viewing of the Games' sailing events.
The Open Spaces Society says it will be an "ugly intrusion" and stop the public from accessing the usually free area.
Weymouth and Portland Borough Council is considering the application.
If approved, the plan would close off 40,000 sq m of public space.
Spectators would be charged £55 to watch some events from the park, such as the ceremonial medal run, during the Games.
Locog claims the fee will aid "safety and crowd control".
A spokeswoman said: "Nothe Gardens has been selected as a ticketed spectator viewing area due to its view of the field of play.
"Use of the location is subject to planning consent and final operational details are subject to change."
Kate Ashbrook from the Open Spaces Society said: 'We have urged the council to reject this application and to tell Locog to site the viewing structures elsewhere, not on public land."