The start is at the end of Chemin de Rosainruz, behind Rimogne secondary school.
(S/E) Take the path leading to the lake and follow it along the eastern and then northern shores.
(1) Cross the stream, channelled by slates laid on large slabs of slate quarried in the local area. Continue along a gravel path which is in fact an old railway line.
(2) After passing private land on the left, at a major crossroads, turn right then keep to the left (west) of the stream. After 150m, take the small path on the right which follows the stream and climbs gently for about 1500m (this path does not appear on the IGN map). After leaving the stream, join the Bérulle forest road.
(3) Turn right and continue for 700m before turning right towards the Étang de la Passée.
(4) Walk along the pond and its marshy bank (avoid this if it has rained heavily!) and head south to rejoin the boundary paths towards the south and west, remaining at roughly the same altitude.
(5) When the path begins to descend, turning eastwards, you approach the Richolle stream, which you can hear, but you are now on its eastern bank. Join a wide path heading south-east.
(6) Walk alongside a quarry on the left.
(7) Almost opposite the access road to the quarry, find a small path on the right which leads back to the old railway line; take this to the left and leave it almost immediately to cross the Richolle again at the same point as on the way out.
(1) Follow the route taken on the way there to return to the starting point (S/E).