A smiling gecko bursts through a gap in the bark to surprise photographer in West Java, Indonesia in the last decade of March 2025. (Photo by Dzul Duzulfikri/Animal News Agency)

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 Hindu worshipper throws vegetables into the crater as offerings during the Kasada Festival at Mount Bromo in Probolinggo, Indonesia's East Java province, August 1, 2015. Every year people gather for the annual festival where offerings of rice, fruit, vegetables, livestock or money are made to Hindu gods at the active volcano to ask for blessings and assure a bountiful harvest. (Photo by Reuters/Beawiharta)

A zookeeper handles a week-old newborn baby Langur at Bali Zoo on June 19, 2014 in Gianyar, Bali, Indonesia. Javan Langurs are found in Java, Bali and Lombok in Indonesia and are listed as a threatened species due to hunting, agricultural expansion and habitat loss. (Photo by Putu Sayoga/Getty Images)

This picture taken on May 23, 2017 shows visitors posing for photos along a path at an Indonesian hamlet dubbed “the rainbow village” in Semarang, central Java, that has become an internet sensation and attracting hordes of visitors. (Photo by Suryo Wibowo/AFP Photo)

Residents move the wreckage of cars that were swept away by flood in Bekasi, West Java, Indonesia, Friday, January 3, 2020. Severe flooding in greater Jakarta has killed scores of people and displaced tens of thousands others, the country's disaster management agency said. (Photo by Achmad Ibrahim/AP Photo)

A picture made available on 21 July 2016 shows a visitor having a meal from a toilet bowl at “Jamban Cafe” (lit. Toilet Cafe) in Semarang, Central Java, Indonesia, 16 July 2016. The cafe was created by a sanitation expert for education purposes to stress the importance of using a dedicated toilet and keeping it clean to prevent disease. (Photo by EPA/Purwanto)

Children try to push an injured and weak dolphin back into the water after it washed ashore during bad weather and high tide on a beach in Cilacap, Central Java, Indonesia August 12, 2016 in this photo taken by Antara Foto. (Photo by Idhad Zakaria/Reuters/Antara Foto)