Waitomo Caves: New Zealand's underground starry sky Waitomo Caves (3 photos) (photo + video)

The Waitomo Caves in New Zealand are considered one of the country's most impressive natural wonders. Their history spans millions of years: limestone vaults and labyrinths formed when this area was underwater.

Today, it contains an entire system of underground passages and chambers, some of which are open to tourists. The caves' main feature is the rare luminescent organisms Arachnocampa luminosa, found only in New Zealand. On the ceilings, they create the effect of a true starry sky with their soft blue glow.

In fact, these aren't worms, but fungus gnat larvae, which use light to attract prey. Trapped in their sticky threads, the insects become food—thus transforming the underground "galaxy" into a survival mechanism.