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)

Gray whale feeding at the surface and showing it's baleen. (Photo by Christopher Swann/Biosphoto)

A camel is pictured in front of the Saturn tracking complex at the Russian-leased Baikonur cosmodrome in Kazakhstan on October 9, 2018. An astronaut and cosmonaut are due to travel to the ISS on October 11 aboard a Russian Soyuz MS-10 spacecraft from the Baikonur Cosmodrome in Kazakhstan. (Photo by Kirill Kudryavtsev/AFP Photo)

Students from Cambridge University in England make their way home along Trinity Lane after celebrating the end of the academic year at a May Ball in Trinity College on June 18, 2019. (Photo by Joe Giddens/PA Images via Getty Images)

A wave carrying plastic waste and other rubbish washes up on a beach in Koh Samui in the Gulf of Thailand on January 19, 2021. (Photo by Mladen Antonov/AFP Photo)

A picture taken on August 25, 2021 shows a view of the Aletsch Glacier. After hiking for hours across the mountain and a vast expanse of white, Swiss glaciologist Matthias Huss crouches down near the middle of the massive glacier and checks the measurements. Analysis of the data gathered from Aletsch, the largest glacier in the Alps, paints a dire picture of the toll that climate change is taking on the behemoth. (Photo by Fabrice Coffrini/AFP Photo)

Shortlisted: The Life: A narrow strip, Río Tinto, Huelva, Spain. A narrow strip of road divides ochre-coloured and fresh waters. Trees wait on the fresh side of the road opposite the toxic waters of a nearby mine reservoir. (Photo by Roberto Bueno/CIWEM Environmental Photographer of the Year 2021)

A health worker gives a polio vaccine to a girl on a street in Lahore, Pakistan, Monday, June 27, 2022. Pakistan launched a new anti-polio drive on Monday, with the goal to vaccinate a million children across Pakistan. (Photo by K.M. Chaudary/AP Photo)