Travel9 of Europe’s underground marvelsAdventureInto the Underland: Robert Macfarlane on exploring the worlds beneath our feet HistoryWorld War I soldiers created poignant art in the trenchesHistoryThousands of People Live in These Ancient Spanish CavesThe Sacromonte and Guadix caves in Granada have been occupied for centuries. See what life there is like today.This Underground Fire Has Been Burning for 59 Years
