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)

Sarah Gibbons grades a new batch of Maple Syrup at Gibbons Family Farm in Frankville, Ontario, Canada, 31 March 2014. The annual maple syrup season marks the end of the often brutal central Canadian winters and heralds the beginning of spring. The maple tree, whose leaf dominates the Canada's flag, plays both a symbolic and practical role in the identity of Canadians who produce around 95 percent of the world's supply of maple syrup. (Photo by Stephen Morrison/EPA)

Arctic treasure by Sergey Gorshkov (Russia). An arctic fox carries its egg trophy from a raid on a snow goose nest and heads for a suitable burial spot. Finalist 2017, Animal Portraits. (Photo by Sergey Gorshkov/2017 Wildlife Photographer of the Year)

Beyonce and Jay-Z leave Rihanna's 3rd Annual Diamond Ball at Cipriani Wall Street on September 14, 2017 in New York City. (Photo by James Devaney/GC Images)

View of the work “Divided” (2016), within the visual artist's exhibition “Urs Fischer: Lovers”, exhibited at the Museo Jumex in Mexico City, Mexico 31 March 2022. The sensations and emotions of love and life, as well as the energy and forces that create and wear it down, inhabit “Urs Fischer: Lovers”, the first solo exhibition in Mexico by Swiss plastics artist Urs Fischer. (Photo by Alex Cruz/EPA/EFE)

A hummingbird feeds on the nectar from a Mimosa tree in Saugus, Massachusetts on July 30, 2020. (Photo by Joseph Prezioso/ZUMA Wire/Rex Features/Shutterstock)

Carolaine Reis and her son Miguel Alves, residents of the Aglomerado da Serra favela, wear a protective mask against the spread of the new Coronavirus (COVID-19) made by the seamstresses of the Remexe Favelinha studio, in the Aglomerado da Serra favela, on April 13, 2020 in Belo Horizonte, Brazil. Facial masks follow the protocol and guidelines defined by the Ministry of Health. Around 6,000 masks have already been produced. The masks are being distributed to a part of the population and sold throughout the country, in the amount of 5 reais per unit. (Photo by Pedro Vilela/Getty Images)

Dutch cyclist Fabio Jakobsen's bicycle (behind, L) flies through the air as he collides with compatriot Dylan Groenewegen (on the ground, L) during the opening stage of the Tour of Poland race in Katowice, southern Poland on August 5, 2020. The Dutch rider was fighting for his life on Wednesday after he was thrown into and over a barrier at 80km/h in a sickening conclusion to the opening stage of the Tour of Poland. (Photo by Szymon Gruchalski/Forum/AFP Photo)