Parking along the road near the Saint-Agnan war memorial, at the crossroads of the D226 and the small road leading down from the cemetery. Alternative parking at the foot of the church, on this small road.
From place to place, you'll find granite markers with the outline of the lake engraved in Blue (referred to as "LSA markers" in the description), as well as wooden signs with the same purpose.
Red and yellow markings
(S) With your back to the war memorial, turn right (east) onto the D226. Cross the River Cousin (signpost) and walk along the dike between Étang de la Chevrée (on your right) and the southern tip of Lac de Saint-Agnan (on your left). At the T junction, turn left onto the D226 towards Les Michaux (signposted).
No markings
(1) Shortly before the "Les Michaux" sign, look for a trailhead on the left (LSA marker, "Interdit aux véhicules à moteur" sign). Follow the path downhill along a meadow on your right. Then take the footbridge across the south-eastern end of the lake. This leads to a meadow and a new footbridge, which gives way to a footpath leading to a small road.
Red and yellow markings
(2) Turn left onto the small road. Go through a hamlet, then at a fork in the road, take the left-hand lane towards the nautical base (sign).
No markings
(3) At a fork in the road, leave the GRP® continue straight ahead on a track and turn left (east) at right-angles, onto a small tree-lined road (LSA marker).
(4) At the lakeside, turn right at an acute angle onto a track. Then take a wooden pontoon bridge over a peat bog. At the end of the pontoon, at a fork, take the left-hand path and walk along a fence on your right. At a fork in the road, turn right onto a new pontoon.
N.B. On the left, a path made up of two planks of wood leads to a dead end (return trip possible, but of little interest at present).
After leaving the pontoon, pass a chicane and return to a wide path.
Red and yellow markings
(5) Turn left onto the wide track. At a fork in the road, turn left onto a path with a fence on your left and a hedge on your right. At a second fork, also left, into dark undergrowth. At a third junction, turn left again (signposted "No fires"). You'll reach the shore of the lake. The path widens and remains parallel to the lake shore, slightly set back and higher up. Reach the Saint-Agnan dam.
(6) Turn left onto the small road over the dam (not very high). After crossing the second weir, the road veers left.
Very rare Yellow marking + silhouettes of a hiker in Red
N.B. On the 1/25000 map, the path on the left bank of the lake, which we'll be following, is marked "GRP® de Pays du Tour du Morvan". This information is out of date, as the characteristic red and yellow GRP® markings are not to be found on this trail.
(7) Leave the road as it bends to the right and turn left onto a slightly downhill path. At a fork (wooden barrier), take the right-hand path (the left-hand path leads to the lake shore). The path winds through the undergrowth without ever straying far from the lake. Cross a few streams at the north-western end of the lake. Pass a wooden barrier, cross a small parking area, pass another wooden barrier and reach Chapelle Saint-Pierre (headstone).
Continue south behind the chapel on a path winding through fern undergrowth. Cross a path and continue straight ahead (red hiker silhouette). The path widens and climbs. Cross another track, continue straight ahead and, at the T-junction that follows, turn left. Stay on the main path through the forest, ignoring the trailheads at the sides. Go past a wooden barrier (LSA marker) and down a path. Follow the path through the pine forest, with a fenced-in meadow on your left. Climb slightly, pass a wooden barrier and come out onto a small road. Turn left and follow the small road back to the starting point (S/E).