Cross the border at Béhobie and take the N121A towards Pamplona (Iruña in Basque). Take the Oronoz-Mugairi exit and then follow the signs for Bertiz. Park in the large car park at the entrance to Bertiz Natural Park.
(S/E) Head north-west to the entrance to the nature park.
(1) Take the path branching off to the right alongside the botanical garden. Ignore a path branching off to the left and continue until you reach the reconstruction of the charcoal kiln, which has an information board.
(2) Turn left onto the path that runs alongside the charcoal kiln and winds its way up to some low walls, the remains of a structure, with an information board.
Continue along the forest track.
(3) Take the path branching off to the right, heading north-east and downhill, to the Suspiro stream (Suspiroko erreka in Basque).
(4) Cross the footbridge and turn right, heading south-east. Continue along this track until you rejoin the charcoal kiln path.
(2) Return to the car park (S/E) via the same route you took on the way there.