There is an otherworldly land called the Mysterious Isle, Emain, the Land of Women, etc. where a Silver Tree grows. On the tree are singing birds (The birds of Rhiannon-see below) From this tree, sometimes a Silver Branch is taken and used by a fairy/faery/fay to lure a hero to the enchanted place. Once there, it is hard for a mortal to return because everything is perfect (no sin or sorrow, good food, etc.) The hero will likely forget his original home or purpose in life.

The Silver Tree often is an apple tree, and apples in these stories have magical effects. Avalon, known in Geoffrey of Monmouth's History as the Island of Apples, may be another version of the enchanted Celtic land. (The world "Avalon" is probably derived from the Celtic word for apple--"afal" in Welsh.)

Celtic harpers carried a branch, betokening the Silver Branch, from which bells hung, representing the birds on the Silver Tree. The ringing of the bells would announce the harper's coming. The implication is that the harper's songs cast a spell of timelessness like that to be found on the island. Those "enchanted" by the song are carried away in imagination to the Mysterious Isle.

In the district which is called Buellt there is another marvel. There is a pile of stones there, and one stone with the footprint of a dog on it placed on top of the heap. When he hunted the boar Trwyd, Cafall—who was the dog of the warrior Arthur—imprinted the mark of his foot on it; and Arthur afterwards assembled a heap of stones under the stone on which was the footprint of his dog, and it is called Carn Gafall. And people come and carry away the stone in their hands for a period of a day and a night, and on the following day it is found on top of the heap.

Then Arthur fought against them in those days with the kings of the Britons, but he himself was leader of battles [dux bellorum]. The first battle was at the mouth of the river which is called Glein. The second and third and fourth and fifth upon another river which is called Dubglas and is in the district Linnuis. The sixth battle upon the river which is called Bassas. The seventh battle was in the Caledonian wood, that is Cat Coit Celidon. The eighth battle was in Fort Guinnion in which Arthur carried the image of St. Mary, ever virgin, on his shoulders and the pagans were turned to flight that day and a great slaughter was upon them through the virtue of Our Lord Jesus Christ and through the virtue of St. Mary the Virgin, his mother. The ninth battle was waged on the shore of the river which is called Tribruit. The eleventh battle took place on the mountain which is called Agned. The twlefth battle was on Mount Badon, in which nine hundred and sixty men fell in one day from one charge by Arthur, and no one overthrew them except himself alone. And in all the battles he stood forth as victor.