sign up (free!)
Also on these boards
Skocjan Caves in Slovenia. One of the largest underground canyons in the world with the Reka river still carving through it. At 60 meters wide and 140 meters deep, this canyon is a fraction of the Grand Canyon’s size, but the fact that it’s all underground makes it feel bigger. When you cross the canyon via the narrow Hanke Canal Bridge, you’ll see the roaring river far below.