Tunnel (35m x 3m) on the line of the Tip Tramway between the site of the former Maenofferen Upper Mill to the area designated as the tipping area for Maenofferen Slate Quarry. First appears on a plan of post 1910 date held by J. W. Greaves and Sons Ltd.

Western End of tunnel has a retaining wall constructed on northern side to support the weight of the cutting face, and this has been reinforced with a series of metal bars driven into the ground against the face of the cutting. Subsequent movement of the face of the cutting has caused the bars and the retaining wall to move. Eastern End of tunnel has suffered a partial collapse close to the entrance.

Internally the tunnel has been faced with coursed and machined slate blocks. At regular intervals, there are timber roof supports built flush into the line of the wall. Some of the timbers have been removed from tunnel walls. The tramway rails survive within this length of tunnel.

References: Plans referred to are held by J. W. Greaves and Sons Ltd, Blaenau Ffestiniog

Spencer Gavin Smith, RCAHMW, August 2011