Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

A woman carries an inflatable float with the sahpe of a portion of pizza in a Barcelona, on July 18, 2020. Four million residents of Barcelona have been urged to stay at home as virus cases rise, while EU leaders were set to meet again in Brussels, seeking to rescue Europe's economy from the ravages of the pandemic. (Photo by Josep Lago/AFP Photo)

Children walk amid a mirror installation titled “Sea of Mirrors”, featuring digital images of fish in the ocean during a preview tour the day before the show's public opening at the AquaRio aquarium in Rio de Janeiro, Brazil, Wednesday, June 14, 2023. (Photo by Silvia Izquierdo/AP Photo)

17-year-old dance student Amelia Hubbard of Halesowen, West Midlands, takes to the park in south Birmingham, United Kingdom on April 14, 2022 to do some spring moves, as temperatures soar in the UK on Good Friday.(Photo by Peter Lopeman/Alamy Live News)

Members of Brighton Swimming Club brave the early morning temperature to take a dip in the sea east of the pier on January 5, 2022. The club, founded in 1860, is the oldest in England. (Photo by Simon Dack/Alamy Live News)

A plane flies past the moon in west London on Monday, January 17, 2022. The first full moon – the Wolf moon according to native north Americans – of 2022. (Photo by Victoria Jones/PA Images via Getty Images)

A Parisian dances at the installation Electronica, a unique look at the great classics of 20th century electronic music, played under the vaults at the Collège des Bernardins part of Nuit Blanche, an annual evening festival of culture and art on October 03, 2020 in Paris, France. Scaled down this year because of the Covid-19 pandemic, the festival is split across the left and right banks of the city with many outdoor exhibitions to enable social distancing. (Photo by Kiran Ridley/Getty Images)

A bird stands near people waiting on South Padre Island to watch the SpaceX Starship rocket launch from Starbase, Texas, on May 27, 2025. SpaceX mission control lost contact with the upper stage of Starship as it leaked fuel, spun out of control, and made an uncontrolled reentry after flying halfway around the world, likely disintegrating over the Indian Ocean, officials said. (Photo by Sergio Flores/AFP Photo)