The capital and chief castle of Destrigales (Outre-Gales), from which King Lac and, later, his son Erec, ruled. Lac had a superbly endowed castle for his residence.
It is either Carwent in South Wales (R. S. Loomis’s proposal) or a conflation of Caer Nantes ('city of Nantes'), as Nantes takes the place of Destrigales in other Erec romances.
In Parzival, Wolfram refers to the land itself as Carnant, and says that Duke Orilus defeated Erec in a tournament there.
The nearby Well of Lac was capable of repairing the Grail Sword.