From Indonesia to Mexico, via Greenland, our world is packed full of natural wonders. They will leave you open-mouthed, inspire you to travel the world and, most importantly, give you a new-found respect for Mother Nature.
There really is no end to the natural wonders our planet holds. From unexplained flocks of starlings in the English skies to multi-coloured eucalyptus bark in the Philippines, there's a whole host of incredible phenomena that we don't truly understand...
Every year, huge numbers of monarch butterflies make the 3000-mile journey from Canada to Mexico to spend the winter in a state of semi-hibernation in the trees of the Sierra Chincua. It has been called one of the most spectacular natural phenomena in the world, with one migration cycle involving roughly five generations.
In certain areas of Namibia, strange rings of barren land form across large swathes of desert. Known as fairy circles, the patches - which are devoid of all plant life - can reach as much as 15 meters in diameter and it is believed that colonies of termites are responsible for the phenomenon.
It might sound like something out of a science-fiction book, but the Indonesian volcano Kawah Ijen spews flourescent blue lava. Sulfuric gasses released from the crater react with the oxygen in the air to create the incredible effect.
Though these rock formations aren't really known as Avatar mountains, they did inspire James Cameron's fictional world of Pandora. You'll find them in China's Zhangjiajie National Forest Park.
These underwater caves in New Zealand are home to a very particular variety of bioluminescent micro-organisms called glow worms. Once inside, the interiors of the caves look like the starry night sky.
Trapped beneath the icy surface of the Arctic, these methane bubbles make up a small part of a deposit of hundreds of millions of tonnes of the gas. As fascinating as it is, this greenhouse gas is also 20 times more dangerous than CO2.
In many parts of the world, starlings are known to create extremely dense clouds when flying in large groups. This phenomenon often occurs at sunset and can give the impression that the sun has turned black.
This multi-colored eucalyptus is common to the Philippines and is also known as Eucalyptus deglupta. The bark of these eucalyptus trees changes color as the trees grow older, creating a dazzling rainbow effect around its trunk.
On Racetrack Playa, a dry lake in the middle of California's Death Valley, you'll find a strange group of stones which move themselves without any human or animal intervention. For years the phenomenon remained a mystery until a study in 2014 found that in winter a thin layer of ice formed on the surface of the stone, allowing it to be blown along by strong winds.
New Zealand's Moeraki Boulders are huge rocks that formed along the coast thousands of years ago through a process similar to that of making pearls.
Found in Turkmenistan, this infernal abyss is not exactly a natural phenomenon; rather a manmade one. In 1971, a group of scientists tried to exploit a natural pocket of gas, causing methane to be released into the atmosphere. To minimize the damage to the environment, they decided to light the escaping methane, and the hole has been burning ever since.