This circuit is part of one of the four circuits traced in 2008 by Pascal Etienne at a place called "Les Cent Marches". The circuit has been retraced in 2021 and in 2023 by Jean-Jacques Naëls. The whole is homogeneous in level 2 (the arbitrary rating of 2 for each problem will eventually be refined according to the repetitions).
Caution: a hornet's nest can be present near the start of the circuit (it was the case in August 2023).