A swimmer goes for a dip in freezing temperatures at the Serpentine Lake in Hyde Park, central London on December 1, 2023, as temperatures in the capital dip below zero for another night. The Met Office has issued a yellow weather warning for parts of the UK with freezing temperatures and snow expected in large areas. (Photo by Ben Cawthra/London News Pictures)

A person watches Mount Etna, Europe's most active volcano, light up the night sky with eruptions, as seen from Piazzale Funivia dell'Etna, Italy on December 1, 2023. (Photo by Etna Walk/Giuseppe Distefano/Handout via Reuters)

A Germany fan looks dejected after the FIFA World Cup Qatar 2022 Group E match between Costa Rica and Germany at Al Bayt Stadium on December 1, 2022 in Al Khor, Qatar. (Photo by Wolfgang Rattay/Reuters)

People visit an installation by the American sculptor, Carole Feuerman, during the exhibition of her hyperrealistic sculptures at Pier 17 in the trendy neighbourhood of Seaport in New York City on June 1, 2024. (Photo by Milo Hess/ZUMA Press Wire/Rex Features/Shutterstock)

A spectator reacts after a Brazil Volleyball win during Paris 2024 Olympics in Women's Preliminary Round, Pool B Brazil vs Poland at South Paris Arena 1 in Paris, France on August 04, 2024. (Photo by Siphiwe Sibeko/Reuters)

(L-R) Daniel Radcliffe, Emma Watson, J K Rowling and Rupert Grint attend the World Premiere of “Harry Potter And The Deathly Hallows: Part 1” held at The Odeon Leicester Square on November 11, 2010 in London, England. (Photo by Dave Hogan/Getty Images)

A cameraman films “Diana And Callisto” (circa 1556-59) oil painting by Venetian artist Titian as it goes on display for the first time at the National Gallery on March 1, 2012 in London, England.(Photo by Dan Kitwood/Getty Images)

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.