Nietzsche rock in Surlej by the waterfall:

The philosopher and poet Friedrich Nietzsche visited the Engadin for the first time at the beginning of July 1881. Thereafter he spent every summer from 1883 to 1888 in Sils. He would be seen sitting on this stone on the shore of Lake Silvaplana, deep in thought. Here, among other things, he came up with the idea of eternal recurrence - the key concept of his major poetic work, "Thus spoke Zarathustra".