The Odessa Catacombs
A network of tunnels underneath Odessa, Ukraine make up the Odessa Catacombs—which are even larger than the catacombs of Paris. Most frighteningly about these catacombs are the number of people who have died there, either by murder or by simply getting lost and never emerging, for example, a young woman named Masha, took a wrong turn and became lost, perishing in the catacombs in 2005, and her body was not retrieved for two years after that.