A hot air balloon floats over farm fields south of Washington, Ill., as the sun slips behind clouds on the autumn afternoon of Wednesday, September 24, 2014. (Photo by Ron Johnson/AP Photo/Peoria Journal Star)

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)

Interesting photos which can't be united in a certain series quite often come across to me. Therefore I publish simply a small group of separate pictures – enjoy, if it's interesting to you. Photo: “Road Trip!” (Photo by Thad Lawrence)

Female Chimpanzee “Fifi” eats carrots as she sits in her enclosure at Taronga Zoo on her 60th birthday May 21, 2007 in Sydney, Australia. Fifi is the oldest of the Zoo's chimp population, which consists of 19 individuals. (Photo by Ian Waldie/Getty Images)

A protester sprays paint on the window of a bank during a rally against Expo 2015 in Milan, Italy, April 30, 2015. The Milan Expo will open in the city on May 1. Officials are counting on some 20 million visitors to the six month-long exhibition of products and technologies from around the world. (Photo by Stefano Rellandini/Reuters)

Russian Mi-28N from the Berkuty (Golden Eagles) helicopter display team fly in formation during the “Aviadarts” military aviation competition at the Dubrovichi range near Ryazan, Russia, August 2, 2015. The aircraft started dipping down due to back propeller failure and crashed, killing one of two pilots, according to a Reuters photographer and official representatives of the competition. The aviation contest is part of the International Army Games, which are held in Russia from the 1st till the 15th of August with participants from 17 countries, according to organizers. (Photo by Maxim Shemetov/Reuters)

Young Buddhist novice monks play at a Tibetan nomadic summer grazing area on July 24, 2015 on the Tibetan Plateau in Yushu County, Qinghai, China. Tibetan nomads face many challenges to their traditional way of life including political pressures, forced resettlement by China's government, climate change and rapid modernization. The Tibetan Plateau, often called “The Roof of the World”, is the world's highest and largest plateau. (Photo by Kevin Frayer/Getty Images)