A seaside castle ruled by a King Orions (Orians) in the Post-Vulgate Suite du Merlin.
When Arthur set hundreds of infants adrift at sea in a vain effort to destroy his incestuous son, Mordred, the boat came ashore at Amalvi. Orions took the children into his care.
Note
There is a beautiful town called Amalfi on the Gulf of Salerno in southern Italy, which I highly recommend you to visit.
See also
Three Physicians of Salerno | The Legend of King Arthur