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)

Natalie Portman and Tessa Thompson speak at the Marvel Studios Panel during 2019 Comic-Con International at San Diego Convention Center on July 20, 2019 in San Diego, California. (Photo by Kevin Winter/Getty Images)

Festival goers wear Australia day attire at Big Day Out 2012 at the Sydney Showground on January 26, 2012 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images)

Stefan Libon proposes to girlfirend Jess McGarrity in front of a banner message “Marry Me Jess?” on the deck of the Queen Mary 2, at Mrs Macquarie's Chair on Valentines day, February 14, 2012 in Sydney, Australia. (Photo by James Morgan/Carnival Australia via Getty Images)

It's taken roughly five months, but a massive iceberg has separated from Antarctica's Pine Island Glacier. According to NASA's Earth Observatory, the estimated size of this iceberg, named B-31, is around 660 square kilometres (33 km long by 20 km wide) – a city-sized block of ice that has slowly migrated away from the continent, and is now floating out to sea. Take a look at some massive icebergs afloat in the oceans. Photo: File photo of an iceberg floating near a harbour in the town of Kulusuk, east Greenland August 1, 2009. (Photo by Bob Strong/Reuters)

Isabella Busse, 6, walks through floodwater near the Seal Beach Pier during a storm in Seal Beach, Calif., Sunday, January 22, 2017. The heavy downpour on Sunday drenched Orange County in one of the heaviest storms of the year. Fast-moving floodwaters swept through California mountain communities and residents fled homes below hillsides scarred by wildfires as the third in the latest series of storms brought a deluge Sunday and warnings about damaging mudslides. (Photo by Ana Venegas/The Orange County Register via AP Photo)

Metropolitan Police patrol as people party at the Soho district, as the coronavirus disease (COVID-19) restrictions ease, in London, United Kingdom on April 16, 2021. Pubs and Restaurants are expecting good business tonight being the first Friday night after Coronavirus lockdown rules were relaxed to allow outside dining and drinking. (Photo by Henry Nicholls/Reuters)

A screen grab from a police body camera video shows the pilot of a plane that crashed on railway tracks being rescued by Los Angeles Police Department officers moments before a train hit the aircraft in Los Angeles, California, U.S. January 9, 2022. (Photo by LAPD/Handout via Reuters)