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 visitor and autumn foliage are reflected in the lake at Stourhead gardens in Wiltshire, Britain, November 2, 2018. (Photo by Toby Melville/Reuters)

A flock of starlings flies over Lake Leman on an autumn morning in the Lavaux near Grandvaux, Switzerland October 20, 2016. (Photo by Denis Balibouse/Reuters)

A white ibis takes a shower at Lake Eola in Orlando, Florida, US on September 29, 2025. (Photo byRonen Tivony/NurPhoto/Rex Features/Shutterstock)

In this photo taken Wednesday, October 29, 2014, a fisherman catches a fish near the shores of Lake Chivero, west of Harare. Illegal fishing can be hazardous in Zimbabwe, where poachers scan the banks for armed rangers and the water for crocodiles while they cast their rods. The country is in such a dire economic state that thousands of people, unable to find regular work, flock to Lake Chivero in hopes of catching fish, mostly bream, that they can sell for desperately needed income. (Photo by Tsvangirayi Mukwazhi/AP Photo)

A participant Saint Nicholas parade walks from house to house dressed in the traditional devil and Nicholas costumes in Francova Lhota district of Zlin, Czech Republic on December 3, 2017. This type of parade is one of the most popular age old tradition in a few villages in Wallachia region (eastern part of Czech Republic). Saint Nicholas walks the streets going from house to house three days and Saint Nicholas gives sweets to children and the devils get up to mischief. (Photo by Lukas Kabon/Anadolu Agency/Getty Images)

A vervet monkey passes in front of a woman on the shores of lake Naivasha, Kenya January 24, 2017. (Photo by Goran Tomasevic/Reuters)

Fireworks explode over a floating Christmas tree in Lagoa Lake in Rio de Janeiro. (Photo by Victor R. Caivano/Associated Press)