This is a single track tunnel immediately west of Firth Viaduct and east of the former Dalmore Mill, Auchendinny Tunnel, Auchendinny Viaduct and Auchendinny station.
The line closed in 1967 and the tunnel now carries a foot and cycle path and is fitted with lighting.
Nearby stations Auchendinny Glencorse Rosslynlee Hospital Halt Eskbridge Rosslyn Castle Rosslynlee Roslin Pomathorn Halt Penicuik [2nd] Rosewell and Hawthornden Polton Loanhead Lasswade Leadburn Bonnyrigg | Dalmore Mill Firth Viaduct Auchendinny Tunnel Auchendinny Viaduct Glencorse Viaduct Glencorse Tunnel Tin Tunnel Rosslyn Gunpowder Works Greenlaw Colliery Loanstone Sidings Penicuik Gas Works Tourist/other Glencorse Barracks Firth Crossing Rosslynlee Hospital Glencorse Old Kirk |
Location names in dark blue are on the same original line. |
An Illustrated History of Edinburgh's Railways | Forgotten Railways: Scotland | Old Penicuik |