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.

A boy shoots a World War II machine gun armed with blanks at an weapon exhibition during a military show near Kirovsk, about 30 kilometers (19 miles) east of St. Petersburg, Russia, Sunday, January 21, 2018. (Photo by Dmitri Lovetsky/AP Photo)

Star Wars enthusiasts wear costumes resembling what they say are three “Chew's Angels” during the 2015 Comic-Con International Convention in San Diego, California July 10, 2015. (Photo by Mario Anzuoni/Reuters)

A high temperature alerts were issued as a record-setting summer heat wave continued to bake most parts of south China. (Reuters)

Karis, a one month old lion cub being weighed at Blair Drummond Safari Park near Stirling, Scotland, Thursday October 10, 2013. Weighing in at 5kg, the cub will stay with her mother, Teekay until she is 12 weeks old before they are returned to the pride. (Photo by Andrew Milligan/AP Photo/PA Wire)

Dancer and musician Seira Soraya, plays the trumpet near Bow Bridge in Central Park on November 09, 2020 in New York City. Soraya has been out of work due to the coronavirus (COVID-19) pandemic and is using this time to work on a personal project. (Photo by Alexi Rosenfeld/Getty Images)

Year of the Rabbit celebration's in Dublin, Ireland on January 29, 2023: Wang Zhi Ning during her Peking Opera Solo performance. (Photo by Nick Bradshaw/The Irish Times)

Four-year-old Eve Hill enjoys the wet weather in York, northeast England on August 2, 2023. (Photo by James Glossop/The Times)