Located in East Java, Indonesia, Kawah Ijen is a volcano is home to the largest acidic crater lake in the world. What turns the waters of the lake in the 1 km caldera its beautiful turquoise color are the highly sulfuric gases emitted from the volcano underneath.

Tourists take a “selfie” as demonstrators burn a trash container during a May Day rally in Barcelona, Spain, on May 1, 2014. Tens of thousands of workers marked May Day in European cities with a mix of anger and gloom over austerity measures imposed by leaders trying to contain the eurozone's intractable debt crisis. (Photo by Manu Fernandez/Associated Press)

Russian Police academy female cadets march during a rehearsal for the Victory Day military parade at Dvortsovaya (Palace) Square in St Petersburg, Russia, Wednesday, May 7, 2014. Victory Day, marking the defeat of Nazi Germany, is Russia's most important secular holiday celebrated on May 9. (Photo by Dmitry Lovetsky/AP Photo)

A woman falls while slipping on ice during freezing rain on Roosevelt Island, a borough of Manhattan, in New York January 5, 2014. New York City was hit on Friday by the first severe winter storm of 2014 and was still in the grip of sub-freezing weather on Sunday morning. The woman got up and walked away from the fall. (Photo by Zoran Milich/Reuters)

Catherine, Duchess of Cambridge speaks to soldiers as she arrives at Calgary Airport on July 7, 2011 in Calgary, Canada. (Photo by Chris Jackson/Getty Images)

“Francois' langur is one of several species of leaf monkeys. Over 50% of its diet is made up of young leaves. It will also consume fruits (17.2%), seeds, flowers, stems, roots, bark and occasionally minerals and insects off of rock surfaces and cliffs. This langur consumes its favorite food, young leaves, at the highest rate during the dry season, April through September, also known as the young leaf-lean period”. – Wikipedia

Photo: An endangered baby Francois' Langur monkey called Laa Laa settles in following her July 6 birth at London Zoo, Regent's Park on August 5, 2004 in London. The bright ginger youngster was born to glossy black parents Max and Shaneka and has the typical orange baby coat which is in stark contrast against the black of her parent's and older brother Grub's fur. (Photo by Steve Finn/Getty Images)

A girl laughs while unloading her boat of produce at a market in Ganvie on January 6, 2012 in Cotonou, Benin. Often called the Venice of Africa, Ganvie is a stilted fishing village on Lake Nokoue, near Cotonou in Benin, the largest such village in Africa, and home to approximately 20,000 residents. (Photo by Dan Kitwood/Getty Images)

«Mignon 2». A.E.G., Berlin, Germany, 1905. Despite its unusual appearance, the Mignon typewriter is of a very clever design, giving a smooth and fast operation for typing. (Photo and caption by Martin Howard/Martin Howard Collection)