Old alabaster Edya, flame of the west, land of rice and towers and white-gold tiles, is an ancient kingdom west of the mountains. It was long inhabited, but flooded, centuries ago, after a great battle, and has ever since laid in water-lapped ruin.
When old explorers from the Cauldron first came to the sunken ruins of Erungalar, they marveled at the clear blue water lapping against the white tile walls. Those tiles looked so good, they thought, in a watery setting. They brought some home and showed everyone they knew. This is the origin of bathroom tiles.