After dark, hike up a hill or a mountain, take binoculars with you: look down at the lights in the valley through the field glasses from up above – now think of something real funny and burst out with laughter: observe the light images that get created in the oculars as you do so
„Light Images – Imagination for Hills and Mountains“, 1994, Reto Jeltsch, imagination/instruction text piece
This imagination can be performed in different places/mountain sites in Switzerland but also worldwide