A petition to keep the land in public ownership had received some 20,000 signatures
A plan has been agreed that will see almost 5,000 acres of land in the Dublin Mountains bought by the Government.
The Department of Arts, Heritage and Gaeltacht Affairs has reached a deal to purchase 4,900 acres of the Dublin Uplands - an area known popularly as the Featherbeds.
This land will be added to the Wicklow Mountains National Park, expanding the total size of the park to 22,000 hectares.
It will effectively stretch the national park from the Wicklow Mountains into the Dublin Mountains.
The announcement comes less than a week after the Green Party presented a petition to the Government - signed by 20,000 people - calling for the Glenasmole Valley to be retained in public ownership.
The outcome is the result of engagement between the department and the National Asset Management Agency (NAMA).
Minister of State Michael Ring said: "The Featherbeds are an important area for nature conservation and for public amenity. Their acquisition by the State is a sign of our enduring commitment to preserve our natural heritage for future generations of citizens and visitors alike to enjoy."
"I believe an exceptional opportunity has been realised for the State in terms of the environmental gain and the amenity potential," he added.
The National Parks and Wildlife Service will work with the Dublin Mountains Partnership to manage this new acquisition.
Green Party leader Eamon Ryan has also welcomed the development.