Undated BBC handout photo of a female two-coloured Mason Bee carrying a dried grass stalk back to her snail-shell nest on the British Isles in the latest episode of Sir David Attenborough's Wild Isles series. Issue date: Sunday March 26, 2023. (Photo by John Walters/Silverback Films/BBC/PA Wire)

A Colombian flower grower selects a rose for a bouquet ahead of Valentine's Day in Subachoque, February 2, 2015. Colombia is the world's second-largest flower exporter behind the Netherlands. The Andean country exports around 500 million flowers to the U.S. for Valentine's Day, according to the Colombia Flower Growers Association. (Photo by John Vizcaino/Reuters)

People pause at a memorial set up for victims of a mass shooting in Las Vegas, Nev., on Tuesday, October 3, 2017. A gunman opened fire on an outdoor music concert on Sunday. It was the deadliest mass shooting in modern U.S. history, with dozens of people killed and hundreds injured, some by gunfire, some during the chaotic escape. (Photo by John Locher/AP Photo)

Two young women pose for a portrait, dressed in robes after collecting their Bachelor degrees in Conakry on October 12, 2020. Presidential elections are to be held on October 18, with incumbent President bidding for a third term in office, defying critics who say he forced through a new constitution this year enabling him to sidestep two-term presidential limits. (Photo by John Wessels/AFP Photo)

Gail Couillard, of South Burlington, Vermont, waits with her dog, Lyndon, for Republican presidential candidate, former U.N. Ambassador Nikki Haley to take the stage at a campaign event at the DoubleTree Hotel on March 3, 2024 in South Burlington, Vermont. Despite having lost every state primary thus far to former President Donald Trump, Haley intends to stay in the Republican race at least through Super Tuesday on March 5. (Photo by John Tully/Getty Images)

Poland's Daria Pikulik, Poland's Wiktoria Pikulik and Britain's Elinor Barker (R) crash as they compete in the Women's Madison race during the fifth day of the UEC European Track Cycling Championships at the Omnisport indoor arena in Apeldoorn, on January 14, 2024. bark (Photo by John Thys/AFP Photo)

Ngorongoro Crater (Tanzania). At 610m deep and 260 sq km, this is the largest unflooded caldera in the world. A blue-green vision from above it's a haven for engangered wildlife and Maasai livestock. The crater was formed three million years ago when a giant volcano, which could have been as high as Kilimanjaro, exploded and collapsed. The caldera formed the concentric fractures in the crust cracked down to a magma reservoir deep underground. (Photo by John Bryant/Getty Images)