Skyspace, James Turrell, Kieder, Northumberland, Scotland, ~1984
"To enter James Turrell's Skyspace you have to pass through a tunnel in the hillside, like the passages that led into the neolithic barrows once built in places like this. Crossing this threshold, you are invited to worship the sky.
The Skyspace is a circular white-walled room with a bench round the circumference and a circular hole in the roof. The hole is like the pupil of an eye fixed unblinkingly on the heavens. You can sit, or better still lie, on the bench and watch the sky move across the aperture. Everything speeds up: you realise how fast things change when you concentrate on the same bit of sky. Clouds unravel. For a while - if you're lucky - the sky turns completely blue."