Most of the city's 19th-century houses were built of limestone mined nearby. Abandoned mines were later used and broadened by local smugglers. This created a gigantic, complicated labyrinth of tunnels beneath Odesa, known as the Odesa catacombs. During World War II, the catacombs served as a hiding place for partisans and natural shelter for civilians, who were escaping airplane bombing.
Most of the city's 19th-century houses were built of limestone mined nearby. Abandoned mines were later used and broadened by local smugglers. This created a gigantic, complicated labyr?inth of tunnels beneath Odesa, known as the Odesa catacombs. During World War II, the catacombs served as a hiding place for part!isans and natural shelter for civilians, who were escaping airplane bombing.