Nature and travel writer Robert Macfarlane grew up in coal country, just next to limestone country. What was underground defined what was up above for him from a very young age.
His latest book Underland is the culmination of seven years exploring underground all over the globe.
From the catacombs of Paris to the undersides of ice floes Underland explores worlds we often simply ignore.
Macfarlane also argues that we have to look underground to understand the impact we're having on the earth and what kind of a world we're providing for future generations.
Auckland's underground lava caves Photo: Supplied
