For tens of thousands of years, caves have captured and fostered the human imagination. They're the closest thing to an alien world most of us will ever experience, and much like the bottom of the ocean, they continue to demonstrate how little we know about our own planet. Here's a look at some of the world's most stunning, inspiring, and spectacular caves.
Waitomo Glowworm Cave (New Zealand)
The glowworms that give the Waitomo Caves their celestial ceilings use their bioluminescence to lure flying insects into sticky, beaded strands of mucous. More relevant to humans, they look really cool. So does the 52-foot waterfall that still flows during heavy rain. Tours are available, though the number of visitors allowed in is dependent on air quality, temperature, and humidity readings taken with the glowworms' health in mind.
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