Sacred geography of the forest of Brocéliande

During the neolithic, Celtics druids and kings used to be buried in a sacred place about twelve kilometers in diameter. This giant necropolis is what we call today "the forest of Brocéliande". Opposed to a modern, distorted vision of an amusement park, Franck Gardian invites us to comprehend the sacred dimension of that "greenness sanctuary" and describes the Mecca of this forest: their place names, their geographic disposal, their legends and the archetypes linked to it.

"To modern man, the difficulty is double: first, he has to manage to keep his mental, his intellect shut, to let nature charm him, secondly, he has to find the strength to come back... this place can lead you to madness! ".
What remains of the castle where Lancelot would have grown.? What does represent the "Valley of no return", its seven lakes and its red schist cliff? What vision did man of neolithic had when seeing this temple?