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 man prepares cookies at a small traditional factory for the Eid al-Adha, amid the spread of the coronavirus disease (COVID-19), in Kabul, Afghanistan on July 29, 2020. (Photo by Mohammad Ismail/Reuters)

A Kurdish fighter from the People's Protection Units (YPG) fires his rifle at Islamic State militants as he runs across a street in Raqqa, Syria, July 2017. (Photo by Goran Tomasevic/Reuters)

Coco Gauff of the United States returns the ball to Arantxa Rus of Netherlands during the Mutua Madrid Open tennis tournament in Madrid, Thursday, April 25, 2024. (Photo by Manu Fernandez/AP Photo)

Alysa Liu of the United States performs during the women's short program at the ISU Four Continents Figure Skating Championships at the Mokdong ice rink in Seoul, South Korea, Friday, FFebruary 21, 2025. (Photo by Lee Jin-man/AP Photo)

Three-year-old orangutan from Sumatra, Berani, is pictured at the Pairi Daiza wildlife park, zoo and botanical garden in Brugelette, Belgium on August 2, 2019. (Photo by Yves Herman/Reuters)

A burning tree is seen during a fire in an area of the Amazon rainforest in Itapua do Oeste, Rondonia State, Brazil, September 11, 2019. (Photo by Bruno Kelly/Reuters)

Manchester City's English midfielder Kalvin Phillips (C) pours alcohol in the mouth of Manchester City's English midfielder Jack Grealish (L) as they celebrate on stage following an open-top bus victory parade for their European Cup, FA Cup and Premier League victories, in Manchester, northern England on June 12, 2023. (Photo by Oli Scarff/AFP Photo)