White Ernz

The White Ernz (Wäiss Iernz, Ernz blanche, Weiße Ernz) is a river flowing through Luxembourg, joining the Sauer at Reisdorf. It flows through the towns of Larochette, Medernach and Ermsdorf. The river valley also includes the notable feature of having a twin castle from the 14th century named Larochette Castle.