Val sans retour (the Vale of No Return) is the most famous tourist place of the forest, located near Tréhorenteuc, west of Paimpont.
It is a steep valley dug deep in red shale, the color resulting from the oxidation of the iron ore it contains.
During the 19th century, there have been two competing of locations of the Vale in the forest, the other one of them having been in the vallée de la Marette near the Tomb of Merlin and also including the initial location of the Tomb of Viviane, until Félix Bellamy decided in 1896 that this is the place that inspired the anonymous author of the 13th century to write the episode of the Vale in the Prose Lancelot.

According to the French tradition of Arthurian legend, Queen Morgan le Fay, half-sister of King Arthur, betrayed by her lover, decided to keep all the unfaithful knights as prisoners in a vale of that name.
Only Lancelot, faithful to Queen Guinevere, was able to break the spell, escape, and free the captive knights.

High above the Vale, the rocher des Faux-Amants (Rock of False Lovers) is the spot where Morgan le Fay is said to have turned her lover who betrayed her into stone.
Another location is the Siège de Merlin (Seat of Merlin), a rock overlooking the valley.

A lake that since the 1940s has been known as the Miroir aux Fées (Fairy Mirror) marks the entrance to the Vale.
Nearby stands also the Eglise du Graal (Church of the Holy Grail), a church that features famous images of Morgan and other Arthurian characters in the Vale.
Val sans retour (the Vale of No Return) is the most famous tourist place of the forest, located near Tréhorenteuc, west of Paimpont. It is a steep valley dug deep in red shale, the color resulting from the oxidation of the iron ore it contains. During the 19th century, there have been two competing of locations of the Vale in the forest, the other one of them having been in the vallée de la Marette near the Tomb of Merlin and also including the initial location of the Tomb of Viviane, until Félix Bellamy decided in 1896 that this is the place that inspired the anonymous author of the 13th century to write the episode of the Vale in the Prose Lancelot.
According to the French tradition of Arthurian legend, Queen Morgan le Fay, half-sister of King Arthur, betrayed by her lover, decided to keep all the unfaithful knights as prisoners in a vale of that name. Only Lancelot, faithful to Queen Guinevere, was able to break the spell, escape, and free the captive knights. 
High above the Vale, the rocher des Faux-Amants (Rock of False Lovers) is the spot where Morgan le Fay is said to have turned her lover who betrayed her into stone. Another location is the Siège de Merlin (Seat of Merlin), a rock overlooking the valley. 
A lake that since the 1940s has been known as the Miroir aux Fées (Fairy Mirror) marks the entrance to the Vale. Nearby stands also the Eglise du Graal (Church of the Holy Grail), a church that features famous images of Morgan and other Arthurian characters in the Vale.
Paimpont forest