7 Most Amazing Caves of our World
Cave of Crystals (Mexico): world's largest known natural crystals
Majlis al Jinn Cave (Oman): world's second largest cave cham
Waitomo Glowworm Cave (New Zealand): a glowworms' paradise
Eisriesenwelt Ice Caves (Austria): largest Ice Caves known to man
Cave of the Ghost (Venezuela): so vast that two helicopters can comfortably fly into it
Fantastic Cave Pit (USA): deepest known cave pit in the continental US
Dongzhong Cave (China): a primary school
