Ringwil
From Tolkien Gateway
The river Ringwil was a short and foaming river of West Beleriand that flowed east through the hilly High Faroth north of Nargothrond until it joined the Narog.[1] Where it met the Narog a secret door was built, which was used by Lúthien to escape from Nargothrond when Celegorm and Curufin held her prisoner.
