Deep below the Ukrainian port city of Odesa lies one of the largest underground labyrinths in the world. The Odesa catacombs date back to the early 1800s when limestone was mined for the city's grand buildings. Through the years, the vast subterranean maze has served as a Cold War bunker, a World War II refuge for Soviet fighters, and a hideout for smugglers. Today, local explorers are still mapping the vast tunnel system and discovering new insights into the past.


This article originally appeared on Radio Free Europe/Radio Liberty. Follow @RFERL on Twitter.