The Stag Moat a natural ravine of the Brusnice stream. It got its name because of breeding of deer here in the 17th century.
It was possible to see deer in the Moat till the 18th century. This tradition was symbolically followed in the 20th century, when a bear pen was founded there. Between 2001 and 2007, a tunnel after the design of architect J. Pleskot was bulit through the embankment between the Upper and the Lower Moat. The Stag Moat is open to public in the summer season.