Schwemmland

Schwemmland, which translates roughly to "marshes", is apparently where the ruined castle of Rozrog stands. Dandelion asserts to a wayward knight that he has not found Avalon and Montsalvat as he hoped, but Schwemmland, when the latter mysteriously appears at Geralt and Yennefer's wedding in the short story "Coś się kończy, coś się zaczyna".