National Geographic

Son Doong - the largest cave in the world, Vietnam. National Geographic

Up close encounters with these magnificent mountain gorillas can be overwhelming. National Geographic

Demonstration of the Leidenfrost effect This is a physical phenomenon in which a liquid near a surface that is much hotter than the liquid's boiling point forms an insulating vapor layer. National Geographic

The oldest raccoon died at the age of 31. In the wild, the life expectancy of these animals is much less: 3-5 years. Promiscuity in nutrition affects, and hence the disease. National Geographic

Uluru Falls, Australia. National Geographic

As the common reef octopus moves across a coral reef, it uses chromatophores to change its coloration and appearance to match the substrate underneath. National Geographic