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.

Costumed characters participate in the 30th annual Dragon Con Parade in Atlanta, Georgia, USA, 03 September 2016. Thousands of attendees crowd downtown Atlanta hotels and streets during the Labor Day weekend for the Dragon Con science fiction and fantasy convention, many dressed as their favorite characters. (Photo by Erik S. Lesser/EPA)

Sarayna Biswas, 6, wearing a face mask and dressed as Kumari wearing gold, takes part in a ritual during the Durga Puja festival celebrations at a pandal, or a temporary platform, amidst the outbreak of the coronavirus disease (COVID-19), in Kolkata, India, October 24, 2020. (Photo by Rupak De Chowdhuri/Reuters)

American film director Mike Todd and his actress wife Elizabeth Taylor get into a spat after missing their flight from London to Nice on June 22, 1957. (Photo by AP Photo)

Alien-themed decorations are seen at the Alien Research Center in Hiko, September 19, 2019. Scores of UFO enthusiasts converged on rural Nevada for a pilgrimage of sorts to the U.S. installation known as Area 51, long rumored to house government secrets about alien life, as law enforcement officials beefed up security around the military base. (Photo by Jim Urquhart/Reuters)

A cow sits on an empty beach near Barbate, in Cadiz province, south of Spain, Saturday, February 5, 2022. (Photo by Emilio Morenatti/AP Photo)

An artist (R) gives finishing touches to a New Year mural painted on his house in Chennai on December 29, 2022. (Photo by Arun Sankar/AFP Photo)

Firefighters try to extinguish a fire caught on a passenger train, ahead of the general election in Dhaka, Bangladesh, on January 5, 2024. (Photo by Mohammad Ponir Hossain/Reuters)