30 Once-in-a-Lifetime Adventures You Absolutely Need on Your Bucket List

28. Exploring the Underground Cities of Cappadocia – Turkey

While hot air ballooning over Cappadocia is world-famous, few travelers explore the region’s other hidden wonders—its vast underground cities. Dating back thousands of years, these subterranean labyrinths were carved into soft volcanic rock by early civilizations seeking refuge from invaders. Some of the most fascinating include Derinkuyu and Kaymaklı, which stretch multiple levels deep and feature tunnels, churches, storage rooms, and even ventilation shafts. If you love hidden historical sites, consider venturing into the catacombs of Paris or Rome for a glimpse into underground worlds shaped by time.