Deep in the lush countryside of Wonju, South Korea, is a domed cave that looks out on to a mountain ridge. Seven rust-red figures, composed of stacked iron blocks, pose in the space: sat up, laid flat or hunched over.

The only illumination comes from the mouth of the cave and an oculus carved into its roof. When it is sunny, light from the oculus slowly makes its way across the polished concrete floor; in other seasons, wind, insects, leaves and snow will all drift in.

“People were just in there lying or sitting on the floor,” says Antony Gormley, as we talk in his airy London drawing studio, “watching the landscape through the curtain of rain, listening to the wind in the trees.”