Creux Du Van

The Creux du Van is a natural rocky cirque approximately 1,400 metres wide and 150 metres deep, on the north side of Le Soliat, in the Val de Travers district in the Swiss canton of Neuchâtel. A very well known, amphitheatre-shaped natural attraction, it is at the heart of a nature reservation area of 15.5 km².
Data from: en.wikipedia.org