A Google Earth rendering of a flyover around the Christchurch 360 Trail

A trail project in Christchurch, 25 years in the making, will launch on Saturday.

The 135 kilometre Christchurch 360 Trail opens on October 3 at Wetlands Grove, Bexley, at 11am.

The trail links existing pathways around the perimeter of Christchurch, including the Coastal Pathway, Halswell Quarry, and Brooklands Lagoon and winds through the city's residential red zone.

DEAN KOZANIC/FAIRFAX NZ Dr Colin Meurk is the man behind the Christchurch 360 Trail, which is opening officially on Saturday.

"There has been a huge team of people working on it," founder Dr Colin Meurk said.

"No individual could have orchestrated this on their own."

Meurk, an ecologist, and other community groups began campaigning about 25 years ago to protect the city's natural assets and raise the profile of Christchurch as a bio-diversity "hot spot".

"It was important to think about how we could connect all these things together."

The perimeter walkway concept brought together key features of the city, and after Canterbury's earthquakes, it became important to think about commercial and "spirit-raising" opportunities, Meurk said.

"It's promoting Christchurch as an eco-city."

In 1991, the trail group had its inaugural meeting at Orana Park, but it was not until 2014 that the vision for the trail drew closer to becoming reality.

A "long year" of negotiations with the Christchurch City Council and land owners followed before the route and signage could be nailed down, Meurk said.

The Christchurch 360 Trail was divided into eight legs, each averaging about 17km long.

Meurk planned to start walking to the entire 135km trail after Saturday's official opening, and would lead one of three guided walks on October 4.