Explanation

In 2018, archaeologists discovered the world's largest flooded cave, named Nohoch Nah Chich, in Mexico's Yucatan Peninsula.

The cave measures approximately 15 kilometers (9 miles) in length and 150 meters (490 feet) in depth.

It was explored and mapped by a team of divers and archaeologists, who discovered ancient Mayan artifacts and fossils of extinct animals.