Lake Zug is a lake in Central Switzerland, situated between Lake Lucerne and Lake Zurich. It stretches for 14 km (8.7 mi) between Arth and the Cham-Zug bay. The Lorze as the main feeder river empties its waters into the lake at its northern extremity, but 1 km (0.6 mi) further west issues from the lake to pursue its course towards the Reuss. Due to this poor feeding, Environmental protection is very important as the lake would suffer long term damage if polluted as the second of the rivers, Rigiaa, feeds only a marginal amount into the lake at its southern end. Already a great part of the fauna in the deep parts of the lake has been lost.There are many turtles in the lake.

Arth is a village, a town, and a municipality in Schwyz District in the canton of Schwyz in Switzerland.