The source of the river Vydrica, marked with a wooden board, is located near the Biely kríz mine. One of the now demolished gates of medieval Bratislava was named after this river. Under the name Wydrucha, it is already mentioned in the 13th century. In 1997, tourists modified its spring and marked it with a sign. In the past, the stream was famous above all for its milling activity - for example, in the 18th century there were five mills on Vydrica, and a century later there were as many as nine mills.