Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

A pilgrim prays at Mount Al-Noor, where Muslims believe Prophet Mohammad received the first words of the Koran through Gabriel in the Hera cave, ahead of the annual haj pilgrimage in the holy city of Mecca, Saudi Arabia September 7, 2016. (Photo by Ahmed Jadallah/Reuters)

Camp dwellers pump water from a well at Malkohi refugee camp in Jimeta, Adamawa State, Nigeria on February 19, 2019, four days ahead of the country's General elections set for February 23 after a last-minute rescheduling. Malkohi is a camp for internal displaced who fled their homes as Boko Haram insurgents advanced across north-eastern Nigeria. From their homes on the outskirts of Yola, capital of presidential candidate Atiku Abubakar's home state Adamawa, Malkohi residents say they feel forgotten. (Photo by Luis Tato/AFP Photo)

This Strange Russian Cartoon Shows Mario's Nasty Side and bogatyr or vityaz is a stock character in medieval East Slavic legends (byliny), akin to a Western European knight-errant.

Canadian artist and mother Ruth Oosterman started collaborating with her 2-year-old daughter Eve earlier this year. Ruth takes Eve’s doodles and adds watercolors to them, turning the collaborative works of art into beautiful paintings.

Can a hamster drive a 15-tonne truck? Watch cute little Charlie steer a brand new Volvo FMX in a rough quarry. Will he make it to the top? Please like, share and comment! This is a daring test of the latest steering system. One that's so easy to handle you can steer a heavy truck with your fingertips.

A tourist walks inside the Ice Palace glacier hollow at Hintertux glacier, located at around 3250 meters above sea level, in Zillertal, Austria, 02 March, 2016. The hollow's temperature remains constant at 0 degrees Celsius, in summer and winter alike, and is also used by the University of Innsbruck for scientific research projects. (Photo by Lisi Niesner/EPA)