A railway tunnel unearthed by archeologists in Crich is believed to be the oldest in the world.
The Fritchley Tunnel can be traced back to 1793, two years earlier than the previous record holder.
It was discovered during a £17,900 Heritage Lottery-funded investigation into the Butterley Gangroad, a horse-operated railway built by 1793 to link the Cromford Canal.
Trevor Griffin, who is project managing the work for the Derbyshire Archaeological Society, said: “The tunnel that was generally considered to be the world’s oldest was on the Peak Forest Tramway and was built in 1795.
“There are a couple of tunnels in the North East with claims to be older but one of those no longer exists and the age of the other can’t be proved.”
The tunnel was nearly lost forever when a previous land owner sealed it up in 1977 to build a rockery. However, after a chance meeting between the current owner, John Midgley, 55, and archaeologists, they won funding to excavate the site.
The team used laser scanning to create a 3D computer model of the tunnel. They plan to re-seal it at the end of their project in 2014.