Caves are cavernous and scary places, filled with bats, bottomless pits, and other natural mysteries. In Vietnam, some brave explorers have discovered and mapped the world’s biggest cave.

The Son Doong cave is 262 feet wide throughout most of the passage, and features a 1.6 mile long river and 230 feet stalagmites. For a couple of miles of the passage, the cave measures 460 feet wide.

The previous record-holder, Deer Cave on the Malaysian island of Borneo, is 300 feet wide, but it is much shorter than Son Doong. The Vietnamese terrain, which is filled with similar limestone caves, presented a lot of difficulties to the explorers. The research team surveyed the cave using precise laser technology to assess its size.

Source: National Geographic