What lures people to delve beneath the earth, peering into the dark recesses that exist underground? Simon Cox hears from the urban explorers trying to find the hidden layers of cities that exist deep beneath our feet and the danger how do we cope with it and the fear of being in the darkness in an enclosed space. And as we travel, work and explore in deeper, longer more extensive subterranean networks, he asks what’s stopping us from spending more time there by living underground too?

Simon speaks to former miner Andy Smith, urban explorer Steve Duncan, caving expert Jules Barratt, engineer and psychologist Gunnar Jonsson and urban planners Professor Anne-Marie Broudehoux and Professor Clara Irazábal.

(Photo: Beautiful stalactites in a cave with two speleologist explorers / Photo credit: Shutterstock)