AVENCHES (in German, Wiffisburg), a small town of Switzerland, in the canton of Vaud, about 1½ miles from Lake Morat or Murten. It is the ancient Aventicum, the chief city of the Helvetii. Many objects of antiquity have been found here; and remains of an amphitheatre, of an aqueduct, and of the ancient walls, still exist. Avenches contains 1100 inhabitants.