A mineral bath on a mountain. Below you, a sea of clouds. Above you, nothing.
The Rigi was the first mountain in the Alps opened to tourists. Queen Victoria came. Empress Elisabeth of Austria stayed here. Mark Twain climbed it on a donkey and wrote about it at length. They were all drawn by the same thing: the view.
From Rigi Kaltbad at 1,438 metres, the panorama takes in Lake Lucerne, Lake Zug, Lake Lauerz, and the full spread of the Alps. What makes Kaltbad more than a viewpoint is the mineral bath, a thermal pool on the mountainside designed by Mario Botta, open year-round. You swim in heated water above the clouds. The effect is difficult to describe accurately.
The approach matters. Take the paddle steamer to Vitznau, then the cogwheel railway, Europe's first mountain railway, up through forest and pasture to the ridge. The slowest way is the best way.