Hotel staff practice self-defence skills after a training session given by team member of Special Weapons and Tactics (SWAT) team, in Hangzhou, Zhejiang province, April 7, 2016. (Photo by Reuters/Stringer)

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 Nepalese woman pours milk as she offers prayers to the setting Sun on the banks of the Bagmati River during the Chhath Puja festival in Kathmandu, Nepal, Sunday, November 6, 2016. During Chhath, an ancient Hindu festival, rituals are performed to thank the Sun God for sustaining life on earth. (Photo by Niranjan Shrestha/AP Photo)

Nepalese army personnel pay tributes before the body of a person who died of COVID-19 before cremating the same in Kathmandu, Nepal, Monday, August 17, 2020. (Photo by Niranjan Shrestha/AP Photo)

A Saudi trader wears a mask as he monitors stock information at the Saudi stock market in Riyadh, Saudi Arabia on August 25, 2020. (Photo by Ahmed Yosri/Reuters)

Dana Friedman, a trial lawyer who has spent 6 months of each year growing out his beard for his annual appearance as Santa Claus since 2001, greets children outside wearing masks as a precautionary measure at the Bay Terrace Shopping Center in Queens as the global outbreak of the coronavirus disease (COVID-19) continues, in New York City, U.S., December 6, 2020. (Photo by Caitlin Ochs/Reuters)

A member of Kun Seng Keng Lion and Dragon Dance Association, demonstrates a dance with an ox mask designed for Lunar New Year at a training centre, during an interview with Reuters, in Muar, Malaysia on February 5, 2021. (Photo by Lim Huey Teng/Reuters)

A Tibetan living-in-exile in India attends a peace march during the 62nd Tibetan National Uprising Day in the suburb of McLeod Ganj, the seat of the Central Tibetan Administration in exile, near Dharamsala, India, 10 March 2021. Tibetan Uprising Day is held annually on 10 March and commemorates the Tibetan uprising against the presence of the People's Republic of China in Tibet in 1959. (Photo by Sanjay Baid/EPA/EFE)