Although smaller in overall volume, the Woodingdean Well near Brighton in the UK is the deepest scar that the human hand has cut into the world’s surface. Reaching 390m (1,285ft) underground, it is as deep as the Empire State Building is tall, yet little more than a metre wide – a hairline fracture rather than a crater.

Its origins sound like the material of a Charles Dickens novel. Built to provide water to an industrial school, the workforce comprised members of the local workhouse; the “guardians” apparently believing that the hard labour would be a deterrent to anyone considering the workhouse as the easy way out of their poverty.

If the “paupers” really did have any hopes of malingering beforehand, the backbreaking work must have soon quashed them. Work on the well continued 24 hours of the day, illuminated by candlelight. Squashed in the four-foot-wide shaft, winchmen stood on platforms down the shaft to pass the soil and rock upwards, and bricks downward to their co-workers at the bottom – who cemented them in place to support the crushing weight from above. Eventually, one of these builders apparently felt the earth move beneath his feet. They had finally struck water, and the labourers quickly scaled the shaft before it rose around them.

Today, of course, technology allows us to reach new depths. Powered by explosives and giant pneumatic and electric drills, the TauTona and Mponeng mines in South Africa have broken through around 4km (2.5 miles) of rock. It takes elevators a whole hour to reach the bottom, where the surrounding rock is a sweltering 59C (138F) – requiring giant “fridge plants” to cool the air across the mine. That’s hotter than the hottest temperature ever recorded on the Earth’s surface.