What did St Cado give the devil in exchange for the construction of a bridge?

Answer 1

St. Cado was a sixth-century Welsh prince-turned-monk. In the chapel, according to local belief, if a deaf person puts his ear on the hollow stone known as the pillow of St. Cado, his hearing will be restored. And the bridge to the island was built with the help of Satan, who demanded the soul of whoever crossed the bridge first. St. Cado chased a cat across, dooming it to perdition.