Craig y Ddinas "The Rock of the Fortress" is said to be the last place where the fairies lived.
It is said that under the huge rock, which is in the far western corner of Rhondda Cynon Taf, a great treasure lies hidden underground.
The treasure is guarded by a company of King Arthur's knights, who have slept in the chamber for many centuries and will only awake if someone tries to steal the treasure.
Craig y Ddinas is a popular stop for those exploring waterfall country, including beautiful Sgwd yr Eira