Explore The World's Largest Underwater Cave
The world's longest underwater cave has been discovered near the city of Tulum, on Mexico's Yucatán Peninsula. The new discovery connects two previously known flooded caves into one 346-kilometre-long stretch. The cave holds an important large freshwater reserve that supports great biodiversity. Hundreds of archaeological sites exist in the cave, including evidence of America's first settlers, Mayan culture, and extinct animals.
Never miss a Nat Geo moment
Join our curious community and you'll have access to some great features!
Personalised content reflecting your interests on the site
Watch exclusive videos before anyone else
Favourite content that you like or want to check out later
Free SMS and Email reminders so you never miss a show
Get notified when content that interests you is published
Share your photos on Snap! that could appear on TV
Share your thoughts and opinions on various matters
Receive a monthly newsletter with loads of great content