Georgian men take a break from selling fruit and vegetable at a street market in Tbilisi, Georgia, Wednesday, July 20, 2016. (Photo by Shakh Aivazov/AP 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)

Filipa Martins of Portugal fails to grab the bar as she performs the uneven bars during the Women's All-Around Final at the 50th FIG Artis​tic Gymnastics World Championships in​ Kitakyushu, Japan, 21 October 2021. (Photo by Kimimasa Mayama/EPA/EFE)

In this Thursday, July 19, 2018, photo, a Syrian shopkeeper spraying water as waits for customers at the Hamadiyah market, named after the 34th Sultan of the Ottoman Empire Abdul Hamid II, in the Old City of Damascus, Syria. The celebratory mood in government-controlled areas stems from successive military advances in the past year and an impression that President Bashar Assad, with massive support by unwavering allies Russia and Iran, has won the war or at least militarily defeated the opposition trying to topple him. (Photo by Hassan Ammar/AP Photo)

Swedish brown bears “Fred” and “Frode” play in the snow on January 30, 2014 at the Natur- und Umweltpark (NUP) animal park in Guestrow, northeastern Germany. Despite of icy temperatures, the bear brothers took a break from their winter rest. (Photo by Bernd Wuestneck/AFP Photo/DPA)

A hooded protester throws a petrol bomb to riot policemen during clashes, following a rally marking the 43rd anniversary of a 1973 student uprising against the military dictatorship that was ruling Greece, in Athens, Greece, November 17, 2016. (Photo by Yannis Behrakis/Reuters)

A reveler jumps from a fountain onto the crowd below, after the launch of the “Chupinazo” rocket, to celebrate the official opening of the 2014 San Fermin fiestas in Pamplona, Spain, Sunday, July 6, 2014. Revelers from around the world turned out here to kick off the festival with a messy party in the Pamplona town square, one day before the first of eight days of the running of the bulls glorified by Ernest Hemingway's 1926 novel “The Sun Also Rises”. (Photo by Andres Kudacki/AP Photo)

A woman instructs a boy on how to pose for pictures in front of a mural depicting Soviet pilot Valery Chkalov – who took a non-stop flight over the Arctic and landed in the US state of Washington in 1937 – at Chkalovskaya metro station in Moscow on August 14, 2019. (Photo by Yuri Kadobnov/AFP Photo)