NIGHTBRINGER | The Arthurian Encyclopedia

Trial Castle

Chasteaux del Asai

One of several heathen castles converted to Christianity by Perceval.

Its residents worshipped a Copper Tower, which was full of demons. Perceval cast down the tower and drove the castle’s residents out of the castle. Those who refused to convert where smashed with a magic axe as they exited the castle’s gates.


Source
Perlesvaus | Early 13th century