Back home, Peter marked the puka, or cave entrance ... what they might encounter inside. Pristine freshwater pools are rare in Hawaii’s lava tubes. They may look inviting, but explorers say ...

How, then, does ... it's dark inside. Everybody who has ever photographed it has encountered the same effect. You want to photograph the depths of the cave but the farther back you look into ...

Hidden in a remote cave in eastern Spain sat the traces of ancient visitors. Some came and went, leaving only artifacts to mark their presence. But for others, particularly children, the cave ...

Costa Rica's 'Cave of Death,' found in the district of Venicia, could have this outcome too, for anyone who recklessly pokes their head inside its low-hanging entrance. The levels of CO2 gas ...

Sources inside of Syria estimated that tens of thousands of people are sheltering in caves, according to The New York Times. Those who do not have access to natural caves create underground ...

CONNOR: So how about the stalagmites on the floor, how do they grow upwards ... make these really dramatic limestone features inside caves. Look!

Some noted that photos are only permitted in one area inside the caves, although you're given plenty of time to pose for them, and you can also snap photos of iguanas in the cactus garden that's ...

However, photography and videography are not allowed in any part of the caves, so keep cameras stowed when inside. Visitors are also asked to keep quiet during the boat portion of the tour.