A team of British cave explorers believe they may have stumbled upon the world's largest cave. Found in the middle of a jungle in Vietnam, the cave is about 492 ft. wide and 656 ft. high.

To find the cave, the explorers had to trek six hours into the heart of the jungle, climb down a large chamber and wade through two rivers! Once inside, they spent five days measuring and exploring it. While they currently estimate it to be 6.5km long, they believe the cave extends out even further behind a calcite wall.

The cave, which has been named Hang Son Doong (Mountain River Cave), was first discovered in 1991, by a local Vietnamese man. However, because of strange noises that could be heard from inside, the local people believed that the cave was haunted, and never dared to explore it further. It turns out that the noises were a combination of a gushing river and wind blowing through the cave.

The explorers have taken their initial findings back to London for analysis. They are planning on returning to the cave later this year, to complete their expedition. Meanwhile, if their measurements, taken using a laser measuring device are accurate, the Hang Son Doong will make the current 'biggest cave' title holder, the Deer Cave in Sarawak, Malaysia, appear quite tiny, with its 300 ft. height and 280 ft. width. What an exciting discovery!

Sources: Sun.co.uk, Dailymail.co.uk,timesofindia.indiatimes.com