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 suffering from mental illness sits chained on a bed in his room inside his family home in Curug Sulanjana village in Serang, Banten province, Indonesia March 23, 2016. In a programme launched this year, Indonesia sends teams of workers into often-remote hamlets to help free patients kept in chains and ensure they get the medical treatment they need. (Photo by Reuters/Beawiharta)

Rescuers pull dead whales ashore in Probolinggo, East Java, Indonesia, Thursday, June 16, 2016 during a mass rescue operation of stranded whales. Most of more than 30 stranded whales were managed to be pulled into the deep sea, an official said. (AP Photo/Trisnadi)

In this Wednesday, April 3, 2019, photo, children play in the water on a beach as a mosque collapsed during the Sept. 28, 2018, earthquake is seen in the background in Palu, Central Sulawesi, Indonesia. The earthquake spawned a large localized tsunami that wiped out coastal areas, while liquefaction caused by the shaking turned entire neighborhoods into rivers of sludge. The disaster killed thousands of people, making it the world’s deadliest seismic event in 2018. (Photo by Tatan Syuflana/AP Photo)

Dancers perform the traditional Kuda Lumping in Bogor, Indonesia early November 2022. They are said to enter a trance-like state as they perform, and often claim not to remember the dance once they awaken. (Photo by Sita Gramich/Solent News)

Commuters ride on the roof of a Jakarta state rail train at Cawang train station on January 27, 2012 in Jakarta, Indonesia. (Photo by Ulet Ifansasti/Getty Images)

A rioter smashes the window of a building on October 8, 2020 in Jakarta, Indonesia. Protesters have gathered across Indonesia after the government passed a labor law it claims will boost economic recovery needed due to coronavirus. Critics claim the bill will worsen labor conditions and environmental protections. (Photo by Ed Wray/Getty Images)

Mount Sinabung continues to spew thick smoke into the air in Karo, North Sumatra on October 30, 2020. (Photo by Albert Ivan Damanik/Anadolu Agency via Getty Images)