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 rows a boat on the Dal Lake as a woman holds an umbrella during snowfall in Srinagar February 19, 2015. (Photo by Danish Ismail/Reuters)

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)

Security personnel patrol around West Lake in Hangzhou, Zhejiang Province, China, August 31, 2016. (Photo by Reuters/Stringer)

(L-R) Heidi Klum and Alessandra Ambrosio attend the 2020 Vanity Fair Oscar Party hosted by Radhika Jones at Wallis Annenberg Center for the Performing Arts on February 09, 2020 in Beverly Hills, California. (Photo by Kevin Mazur/VF20/WireImage)

In this Monday, July 24, 2017 photo, a police officer walks in front of a mural during a protest demanding an end to the current pension fund system, in Santiago, Chile. Protesters say the government pension system robs retirees of fair pension payments, and are demanding a new social security system with higher payments. (Photo by Esteban Felix/AP Photo)