Fun goes underground with these 10 subterranean adventures. We've scoured the Earth for tunnels, caves, buried neighborhoods, and other treasures hidden beneath mountains, prisons, and even thriving cities. So go ahead and skip the sunscreen—you're going underground.
Waitomo Glowworm Caves
Waitomo, New Zealand
You: in the dark, on a boat, admiring a twinkling sky. Sounds nice, right? But there's a memorable twist: You're deep underground and those aren't stars, they're living lights—the famous glowworms of Waitomo Caves in New Zealand. The worms, and the experience, are unique to New Zealand. In addition to the boat ride through the Glowworm Grotto, tours of the Waitomo Glowworm Caves include a stop at the Cathedral, a soaring cavern renowned for its acoustics.