Transport Infrastructure Ireland (TII) is looking at a proposal to turn a 36-acre surplus site into a native woodland.
The innovative plan, the first of its kind, would see the land donated to Nature Trust for planting with the type of trees and forest that once covered Ireland.
It would then be managed "into perpetuity" by the trust with walking trails developed for use by the public.
The site was part of a 65.5-acre parcel of land that was bought by TII for a national road scheme in Co Cork.
Once the €280m bypass between Macroom and Baile Bhuirne was complete, the public body no longer had any use for the remainder of the site.
A TII presentation said options open to them included the sale of the land or alternative use, for example, as a solar farm.
However, a new plan was put forward whereby TII and Cork County Council would donate the site to Nature Trust.
The presentation said the site would be developed both as a native woodland and to highlight the historical significance of the area.
According to the records, the site was part of the Coolnacaheragh Battlefield and was the location of the Coolnacaheragh ambush in February 1921.
The TII slideshow said the new forest would be "rich in biodiversity" and help them with their carbon footprint.
"It is estimated that this native woodland will sequester and store an average of 75 tonnes of carbon dioxide every year," said one slide.
TII said "natural carbon woodland credits" would apply and that Nature Trust would provide periodic updates on "biodiversity uplift" and "community engagement."
The slideshow said the plan would help protect soil and water in the locality and create a new public amenity for the area.
TII said they would have further discussions with Nature Trust and look to carry out site assessments.
They would then look at suitable tree types based on soil sampling and plan the woodland with trails and playgrounds.
The presentation said an application would then be made to the Department of Agriculture.
Asked about the plan, a spokesman said: "TII are working in collaboration with Cork County Council and are currently engaged in ongoing discussion with all stakeholders on progressing this proposal."
"TII is committed to placing sustainability at the centre of proposals being made on the use of surplus lands associated with the road improvement projects throughout the national roads [and] motorway network," he added.
Reporting by Ken Foxe
