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.

[6] Not many of the structures from the original Whitby & Pickering Railway exist, and the Horse Tunnel is the only one which is maintained by the NYMR.

[12] The Horse Tunnel is believed to have been designed and built by George Stephenson, who was the overall engineer for the whole route from Whitby to Pickering.

[18] It was designed by John Cass Birkenshaw (the then architect for the Y&NMR), was grade II listed in 1989 and is still used by trains on the NYMR.

The Horse Tunnel is now grade II* listed[21] and is still in use as a thoroughfare to allow visitors to the NYMR access to viewing areas around the engine sheds.