
Swim around the world's longest underwater cave
Divers in Mexico have made an amazing discovery - the world's longest underwater cave.
They found that two underwater caverns in eastern Mexico were connected.
The cave is 216 miles long - which is around the same distance between London and Paris!
Inside the cave, they found pots and other relics left behind by the Mayan people, who lived there over a thousand years ago.
Come and have a swim around!