A hole in the ground?

Well yes and no. This is Baume les Messiers in The Jura Mountains. It's literally a large area which has just sunk leaving vertical cliffs around a green and pleasant valley . This is now home to a 9th century abbey and surrounding village, the Baume caves , purporting to provide a journey to the centre of the earth, and numerous water features being admired by people of all ages. Say no more!