The lake has a complicated shape, with bends and arms reaching from the city of Lucerne into the mountains. It has a total area of 114 km² (44 sq mi), an elevation of 434 m (1,424 ft), and a maximum depth of 214 m (702 ft). Its volume is 11.8 km³. Much of the shoreline rises steeply into mountains up to 1,500 m above the lake, resulting in many picturesque views including those of Mount Rigi and Mount Pilatus.
The Reuss River enters the lake at Flüelen (in the canton of Uri, the part called Urnersee) and exits at Lucerne. The lake also receives the Muota (at Brunnen) Engelberger Aa (at Buochs), the Sarner Aa (at Alpnachstad).
It is possible to circumnavigate the lake by road, though the route is slow, twisted, and goes through tunnels part of the way. Steamers and other passenger boats ply between the different towns on the lake. It is a popular tourist destination, both for native Swiss and foreigners, and there are many hotels and resorts along the shores. In addition, the meadow of the Rütli, traditional site of the founding of the Swiss Confederation, is on the southeast shore of the lake. A 35 km commemorative walkway, the Swiss Path, was built around the lake to celebrate the country's 700th anniversary.