How to get there: coming from Autun on the D680 towards Le Creusot, take the small road on the right at "les Baumes", and then go as far as the pond car park, about 200m away.
(S) Reach the green metal fence that closes off the area at the entrance to the pond. Drive around it to reach the edge of the pond. You'll see a notice board on your right. Continue along the edge of the pond, heading south towards the dike. Be careful, at first the path is narrow at the water's edge.
(1) Take the dike on your left and continue on the track that runs uphill until you reach the bend in the road. Take the tarmac track on your right at Le Martinet and head south-south-west downhill. The tarmac gives way to a gravel path, which you follow until you come to a barrier. Go around it and continue on this path to the Haut Rançon reservoir.
(2) Continue along the track to the water crane (see right), then keep going and you'll see on your left the start of the tunnel through which the water pipe runs to Le Creusot.
(3) After the metal barrier, leave the trailheads on the right and left, and continue straight ahead on the parallel paths, taking the one on the left. Reach a masonry shelter with a metal door (water catchment).
(4) Turn right on the GR® (Red-White markings) and after about 50m, take the path on the left. Use the footbridge to cross the Rivière le Rançon and continue along the GR® to the right. At marker 75, keep to the left. Watch out for the holly bushes (milestone 72), where you'll find a right-hand turn which you need to take straight away, then a left-hand turn which you need to take a few metres further on.
After a steep climb and crossing a wooden footbridge, you come to a path which you should take to the left. After a steep ascent, you come to a gravelled forest road, which you follow until you reach the left-hand turn for the GR®.
(5) Continue left, on the GR®, to the stream. Cross it on the right over two stones, which are easy to climb over.
(6) Immediately take the path on your right (marked Red-White and Yellow).
At the top of the climb, you'll see two paired trees on your left.
After a wet passage, which you must avoid by turning left, you come to a forest house on a small tarmac road, which you turn right onto.
(7) At the star junction, continue on the gravel road (wooden barrier) to the pond (S/E).