One of the Monsal Trail tunnels

Walkers, cyclists and horse-riders are being asked to take care during maintenance work in tunnels on a Peak District trail.

Lighting in the Monsal Trail tunnels will be dimmed while contractors carry out essential work, and users will have to make their way round the movable platform being used.

Maintenance will take place in all four of the tunnels, starting this Friday and will continue for four weeks.

The Peak District National Park Authority said cyclists will have to dismount where contractors are working, and all trail users will need to divert slightly on to ballast at the side of the trail to get round the moveable platform.

Wheelchair users are warned this will be very rough going and they may want to avoid the tunnels while work is going on, the authority said.

Its trails manager Abi Ball said: “There will be warning signs at the tunnel entrance and there will still be lighting within the tunnels at all times. It will, however, be dimmer if that particular tunnel is being worked on, so extra care will be needed by trail users.

“The contractors will be working on one tunnel at a time, starting at Chee Tor tunnel on 26 April and working east onto Litton, Cressbrook and finally Headstone tunnel.”

The 14km (8½-mile) Monsal Trail runs from Bakewell to Blackwell Junction near Buxton. The tunnels are lit during daylight hours, operated by a light sensor, but they are dark at night.

The tunnels have proved a major attraction since the authority re-opened them in May 2011.

Cyclists and walkers can still see soot on the walls from the days of steam engines, and information panels detail the history of the old Midland Railway line that connected the Peak District to London before its closure in 1968.

More details are on the Monsal Trail website.