Lightning appears in a volcanic plume, causing a mud storm.
Desert termites are thought to be behind the "Magic Circles" of Namibia.
This unique landscape, known as the Giant's Causeway, is situated in North Ireland. It was caused by an ancient volcanic eruption.
These rare lenticular clouds were pictured in northern Georgia, USA.
This unique lightning phenomenon in Venezuela sees lightning flashes 140-160 nights per year at a rate of 280 flashes per hour.
43 million Christmas Island red crabs migrate to the ocean to lay their eggs each year.
The Great Blue Hole lies off the coast of Belize. It's more than 300 meters across and 124 meters deep.
"Rough Wave" clouds are pictured above Texas.
Lake Natron is a saltwater lake fed by hot springs. It is found in Tanzania.
The Canadian Spotted Lake is the world's greatest reserve of magnesium sulfate, calcium, and sodium.
The Door to Hell is in Turkmenistan. It's a gas mine that was deliberately set alight four decades ago and hasn't stopped burning since.
New Zealand is home to these spherical boulders, which formed due to erosion.
Icy water freezes around bubbling methane in Abraham Lake, Canada.
Beautiful ice crystals like these form when calm lakes and seas begin to freeze over.
A rumble of some 50,000 starlings flies in formation, creating a "black sun".
The USA's Death Valley is home to a unique natural phenomenon - sailing stones move along the smooth ground completely unaided.
Male puffer fish create these perfectly-aligned circles to attract and impress females.
Swarms of Monarch butterflies migrate annually from Canada to the southern United States.
Rare rain in the driest places on earth, the Atacama Desert, gives life to pink flowers and herbs.
Mammatus clouds are very rare and mainly appear in tropical latitudes. They are usually associated with tropical cyclones.
Luminescent plankton light up the waves washing up on the beaches of the Maldives.
Between May and July, billions of sardines annually head north along the east coast of Africa.
Winnie the Pooh once made an appearance in the sky at a children's charity event in Dorset, England.
An enormous shelf cloud forms off the coast of Sydney. Images of it went viral around the world.
Western Australia, on the other hand, was stunned to see this huge dust storm in early 2013.