The Attersee is the largest lake entirely within Austria — about 20 kilometres long and 3 kilometres wide, with depths reaching 171 metres. The water is cold, clear, and extraordinarily blue-green, and the shores are lined with summer villas, sailing clubs, and small resorts. It is the lake of the Viennese bourgeoisie: for generations, artists, composers, and wealthy families have maintained summer houses here.
For swimmers, the Attersee is best explored by renting a kayak or paddleboard and pulling up on the quiet eastern shore, which has fewer roads and more natural beaches. The sailing is excellent. The Attersee Museum in the village of Attersee am Attersee has an exhibition devoted to Klimt's summers here, including reproductions of his lake paintings and photographs of the painter at work. The originals are spread across major museums in Vienna and elsewhere.