The "Goblin Stone" is located on a lonely moorland ridge by Lampeter, next to the Sarn Helen Roman road. Theories about the site and its original function include that it was possibly a round barrow, a chambered tomb or even a Roman watchtower.
Few would pass the stone at night. In the 17th century, a young man in search of work made the mistake of sleeping next to it. At midnight, someone pinching his arms and ears and pricking his nose woke him. By the dim light of the stars, he saw the form of a goblin sitting on the stone with a number of others around him. The young man tried to make his escape, but the chief goblin ordered his minions to hold him back. They tormented him until first light, at which point the goblins simply vanished. When the unfortunate man related his story to some passers-by, he was informed he had slept under the haunted goblin stone.
The stone is also said to attract lightning strikes and three men were killed here during a thunderstorm. Lightning strikes are attached to treasure and hoard lore;
To touch or dig for buried treasure guarded by a ghost without the ghost's consent will always bring thunder and lightning. Such is the tradition in connection with Carreg y Bwci.
The stone to this day is still associated with mysterious occurrences. There have been recent reports of bolting horses and unusual mists.