Grosmont Tunnel
The Grosmont Tunnels are two separate railway tunnels adjoining each other in the village of Grosmont, North Yorkshire, England. The first tunnel was built in 1835 and has now become a pedestrian route through to the North York Moors Railway (NYMR) engine sheds on the south side of the hill. The original tunnel was superseded by a new bore in the 1840s that was sited immediately west of the old tunnel. The 1830s tunnel is now the only original structure built by the Whitby & Pickering Railway (W&P) that is under the care of the NYMR.
Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).