Tunnel on the GR5 trail Spa-Stavelot under the old railway, now Ravel45.
The railway ran from Stavelot to Spa via Francorchamps.
From Spa the entrance is more difficult to find: on the left side of the guardrail down.
The path goes along with the small stream "Hottonruy" along the tunnel.
Just upstream is La Pierre du Diable:
This huge quartz block remains as a witness to Satan's new attempt to destroy the church of Stavelot.
The day before the ordination of the church built by the holy Remacle, the devil planned to throw a large stone on the roof to destroy the monks and the building.
Alerted by an angel, Remacle had a bag filled with old shoes and put it on the shoulders of one of his disciples he sent him to Satan (according to some versions, Saint Remacle went there himself, others said it was Brother Antonius, guardian of the abbey).
The conversation started at the top of a steep hill, where the devil had just arrived:
Comrade, says the devil, is the abbey of Stavelot far from here?
The monk who empties his bag on the way answered:
These are shoes I've worn since I left Stavelot.
And the devil, discouraged, made a terrible blasphemy to be heard, abandoned the stone and fled away.
According to another version, the devil has marked the stone and thrown it away. He broke into three pieces: that of Wanne, another one in Walk (Waimes) and a third one in Reichenstein, near Montjoie.