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.
Rosslynlee Hospital Halt
Rosewell and Hawthornden
| Dalmore Mill|
Rosslyn Gunpowder Works
Penicuik Gas Works
Glencorse Old Kirk
|Location names in dark blue are on the same original line.|
An Illustrated History of Edinburgh's Railways
Forgotten Railways: Scotland