The condition of the imposing Victorian viaducts and bridges along the Monsal Trail in the Peak District will start to be inspected next week.
Experts will use rope and harness techniques, originally developed by rock climbers and cavers, to take a closer look at the structures and make recommendations for any work required, as well as removing plants which could be causing damage.
The 8.5-mile trail, which starts just north of Bakewell, will remain open to the public throughout the inspections.
It is estimated that more than £2m will need to be spent on structures on the trails over the next six years.
To help raise the money a major fundraising event, Walk in the Park, will be held along the Monsal Trail and at Bakewell Showground from August 19 to 21.