An East Sussex coastal site said to be internationally important for fossils found in the cliffs is being opened as a local nature reserve on Saturday.
The park already attracts more than 500,000 visitors each year
Hastings Country Park is also said to be the largest local nature reserve to be declared in 20 years.
The council said it was one of the few UK sites where dinosaur bones and footprints could be found in the rock.
It said the park, with views stretching to France, already attracted more than half a million visitors each year.
Iron Age fort
The park will be opened by Professor David McDonald from English Nature.
Councillor Peter Pragnell, leader of Hastings Borough Council, said it was a "fantastic asset".
He said features included huge flocks of birds feeding on farmland, spectacular bird migration, insects that could only be found at a handful of coastal sites, and a cliff top Iron Age fort.
Mr Pragnell said the designation would allow the council "to get the best from this amazing and popular attraction" and added that it was "the jewel in the crown of nature reserves in the town".