Walchensee is one of the deepest and clearest alpine lakes in Germany, lying at about eight hundred metres in the Bavarian Pre-Alps, with a surface the colour of turquoise glass on a good day and dark green on a stormy one. The lake is surrounded by forested mountains, with the Herzogstand and the Heimgarten rising to the north, and it has a calm, almost Scandinavian look in the early morning.
The approach is the thing. From Kochel am See, the B11 climbs the Kesselberg in a series of hairpins and tight curves, rising about two hundred metres in a few kilometres, with the old road snaking up through beech forest. The gradient is steady, the surface is generally good, and the road is a classic for riders, which is also its problem: it is crowded at weekends, the noise is a source of friction with locals, and restrictions on motorcycles have been introduced and changed in recent years. Check the current rules before you go and expect speed limits and police checks on busy days.
The lake is also home to a major hydroelectric scheme. In the early twentieth century, the engineer Oskar von Miller realised that the water of Walchensee could be dropped about two hundred metres down to the Kochelsee, and the power station that he built opened in 1924. It supplied electricity to Munich and the railways for decades, and it still operates, a remarkable piece of engineering hidden in the hillside. The painter Franz Marc lived in nearby Kochel, and his bright, colourful animals are celebrated in a museum in Kochel itself.
The water is clean and cold, and in summer it is popular for windsurfing and sailing, since the afternoon wind is reliable. Swimmers should expect a chill, even in August. The village of Walchensee has fuel, cafes and a few small guesthouses, and Kochel and Mittenwald offer more choice. Go early in the morning, when the lake is still and the road is empty, and you will understand why people queue for this place.