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.

CANNES, FRANCE - NOVEMBER 03: Italian Prime Minister Silvio Berlusconi leaves the conference centre after the first day of the G20 Summit on November 3, 2011 in Cannes, France. World's top economic leaders are attending the G20 summit in Cannes on November 3rd and 4th, and are expected to debate current issues surrounding the global financial system in the hope of fending off a global recession and finding an answer to the Eurozone crisis. (Photo by Dan Kitwood/Getty Images)

In this June 16, 2017 photo, Batel Delciner, 23, removes wood from a furnace to lower the heat cooking sugar juice at the Ti Jean distillery, which produces clairin, a sugar-based alcoholic drink, in Leogane, Haiti. The broth is cooked for about four hours after a fermentation period of four to eight days. (Photo by Dieu Nalio Chery/AP Photo)

In this Friday, May 10, 2019, file photo, rescuers help a baby wild elephant cross the wetland to return to the forest at Deepor Beel wildlife sanctuary in Gauhati, India. The elephant had gotten stuck in the waters of Deepor Beel after it was separated from a herd of wild elephant that came down in search of food last night. (Photo by Anupam Nath/AP Photo)

“Honorable Mention”. An Indian rhinoceros, far from home and stuck inside with late-winter blues at the Toronto zoo. Photo location: Toronto, Ontario, Canada. (Photo and caption by Stephen De Lisle/National Geographic Photo Contest)

A man sits on his cart which he attached with National League for Democracy (NLD) party flags along a flooded street in Yangon September 30, 2015. Myanmar will hold a general election on November 8. (Photo by Soe Zeya Tun/Reuters)

Customer Andreas Kroker looks at a 3D-printed figure of himself at the Twinkind 3D printing studio in Berlin, December 13, 2013. A 3D-printed likeness is produced by taking a 360 degree photographic scan of a person, which is then rendered into a 3D digital model and retouched to meet the requirements for printing. The printing machine uses this digital model to produce a high-resolution solid figure. Twinkind co-founder Timo Schaedel said, people often come to the session well-groomed, with fresh hair-cuts and their best clothes, “just as they used to do in the past, when they had their portrait taken in a photo studio”. (Photo by Thomas Peter/Reuters)

A boy dressed like Hindu Lord Krishna waits to attend celebrations on the eve of Janmashtami at a school in Mumbai, India, Friday, September 4, 2015. The day marks the birth of Krishna. (Photo by Rajanish Kakade/AP Photo)