According to legend, whenever the wizard Merlin could get away from affairs of state at the court of King Arthur, he would return to his lover, Viviane, in the forest of Brocéliande.
In the forest, the fountain of Barenton is reputed to be the spot where Merlin first met Viviane, who was the daughter of the Lord of nearby Comper Castle. The castle’s lake is said to cover the palace that Merlin magically built for her. The fountain is also claimed to be the spot where Yvain, one of King Arthur’s Knights, defeated the Black Knight, the fountain’s guardian.
One day, Viviane implored him to teach her his magical arts and gradually she learned all his magic. It is this knowledge that she used finally to imprison Merlin in nine invisible rings – a prison of air – to keep him from leaving her again to return to his duties at Arthur’s court. It is said that Merlin’s Tomb hides this prison of air.