Concerns have been raised about extensions to a tunnel on the Keswick to Threlkeld Railway Trail will make the portal the shape of a World War Two Nissen hut.
Work has been ongoing to extend the tunnel, near Low Briery, to help with the stability of the slope.
Eric Bainbridge, of Keswick, said: “The approach to the tunnel, with the beautiful shaped Victorian horseshoe and the sandstone retaining wall will now be lost forever, covered over by a concrete extension.
“What you will see now is an entrance to the tunnel which looks more like the shape of a World War Two Nissen hut.”
He added that he was concerned that the stone that will be used to face the tunnel was coming from China and not from a local quarry.
Mark Eccles, head of park management at the Lake District National Park Authority, said the tunnel has been extended at its east and west ends and that it had been surveyed and photographed prior to the extensions being added.
He said: “The extensions have been done to mitigate slope stability concerns and any subsequent negative impact on the A66 given the tunnel and the old cuttings were in-filled at the time the A66 flyover was built.
“The original tunnel portals remain intact despite being hidden from view once again.
“New tunnel portals will be finished using stone facing to be in keeping with the railway heritage.
“Stone facing material has been imported as the lead-in times and costs were unfortunately prohibitive for locally sourced material.
“But the stone was sourced in a way to ensure they provide a good match to previous materials used on the railway infrastructure along the line.
“It will be good to be able to bring the old tunnel back to use and it will be once again above ground for people to see and enjoy.
“And its reopening means the entire trail will be accessible to all given it replaces the boardwalk that was a limitation for some users.”
