Lake Lucerne

The fourth largest lake in Switzerland, formed at the end of the last ice age from the meltwater of the Reuss Glacier as it retreated between 20,000 and 15,000 BCE, the same melting that made most of the lakes in central Switzerland. Its German name, Vierwaldstättersee, dates only from the sixteenth century; before that the whole lake was simply Lake Lucerne, which English has kept. The three Waldstätten were the confederate allies of Uri, Schwyz and Unterwalden, and the fourth, Lucerne, was added to the count in the 1450s.