A handful of men, including Griffin's brother Connor Bruce Lyonss), take the boy's advice and, as you do, dig a tunnel deep into the bowels of the earth in an attempt to find "the far side of the world".
Castles made of stone, of wood, of ice; with passageways tunnelling deep into the ground, or spiralling high with turrets and stairways.
"Chicago" is the longest section of his memoir, and in many ways the bleakest, for it tunnels deep into the bedrock of inner-city despair and inadequate politics and black selfdestruction.
He was one of those soldiers, moreover, who with grim humour called themselves "claykickers", whose job it was to dig tunnels deep into the mud and plant bombs under enemy lines.
"Farm equipment lies tangled in lace; mice and squirrels have incorporated threads and needles from sewing baskets into nests or tunneled deep into the opulence of damp horsehair and straw," the photographer Rosamond Purcell wrote in a book about Mr. Buckminster, "Owls Head: On the Nature of Lost Things".
Most triumphantly of all, let's head to Radio 1's Newsbeat where, with classic Walshean logic, Louis has tunnelled deep into the heart of the problem with TV singing shows, noting that they're "not what they used to be – they have too much singing in them".
Humans have tunnelled far deeper into the Earth's crust, however, using little more than blood, sweat and a spade.
A multi-row distribution of the guide holes shaped like a quincunx can increase the interconnectivity of the plastic areas and allow the plastic area to extend from the tunnel wall deep into the surrounding rock.
Several of these experiments are taking place at the Gran Sasso National Laboratory in central Italy, the world's largest underground laboratory, which lies beneath almost a kilometre-and-a-half of solid rock and can only be reached through a tunnel cut deep into the Italian Apennines.
