A campaign has been launched to save an historic 85-acre wood which environmentalists fear is under threat from a proposed new bypass and housing.
But opponents fear the road would have to pass through the Old Park and Chequer's Wood, which is a haven for wildlife and family recreation.
The scheme is one of two relief roads being promoted by the city council - the other being a western bypass at Harbledown, which also faces opposition.
The authority believes the new roads will reduce gridlock in the city centre, but exact routes have yet to be decided.
Leader Cllr Ben Fitter-Harding said previously: "We're not at the point yet where we're saying 'a road is going to go through this specific place'.
"These are just options we are considering."
But a group of about 35 campaigners recently trekked 4.5 miles through the woods they believe are at risk.
The event was organised by William Rowlandson, who says pushing ahead with the road scheme would be "environmental, social and economic folly".
"The walk provided a great opportunity for people to see the precious nature of Old Park and Chequer’s Wood, the rich ecosystems of grassland, heath, woodland and wetland, and to comprehend the scale of the destruction which the eastern bypass would cause," he added.
Campaigners - who also fear a new bypass will bring with it more housing - have launched a petition on Change.org, which has already gained more than 1,200 signatures.
It has been created by University of Kent conservation biologist Kate Allberry, who says the petition acts as a platform for the wider community to voice their support for the campaign.
She hopes people will express their own reasons as to why Old Park and Chequer’s Wood need to be protected.
To support the campaign, a colour leaflet has also been produced, highlighting the special value of the wood and the potential threat it faces.
So far, 3,000 copies have been produced and distributed in the local area.
A new Friends of Old Park group was also due to be launched at an open meeting at 2pm yesterday (Saturday) at the Northgate Ward Community Centre.
"We're not building more roads to put more traffic out there, we're trying to reduce traffic..."
One of the organisers, city councillor Pat Edwards (Lab), said: "We have a responsibility to address ecosystem breakdown, unprecedented biodiversity loss and rising public health challenges right here on our doorstep.
"The future of an ecologically important area like Old Park and Chequer’s Wood is an important test case to see whether Canterbury City Council has the political will to put words into action."
But Cllr Fitter-Harding says: "If we want to liberate the city of Canterbury from congestion and air quality problems, we need to relocate the traffic to roads which are suitable.
"We're not building more roads to put more traffic out there, we're trying to reduce traffic."