The Cotopaxi volcano, one of the world's highest active volcanoes, spews smoke as seen from El Pedregal, Ecuador, October 22, 2015. Ecuadorian authorities are monitoring activity at Cotopaxi volcano, which prompted Ecuador's President Rafael Correa to maintain a yellow alert for eruptions as bursts of ash keep spewing from the snow-encircled crater of the volcano and falling in gusts on residential communities. (Photo by Guillermo Granja/Reuters)

A round circle of smoke coming from the mouth of the Etna volcano is seen in the sky during an eruption on the southern Italian island of Sicily April 11, 2013. Mount Etna is Europe's tallest and most active volcano. (Photo by Antonio Parrinello/Reuters)

People look at the Turrialba volcano as it spewes ashes on May 20, 2016, in Cartago, Costa Rica. The Turrialba volcano started erupting columns of smoke and ash that the wind extended towards the Costa Rican capital, in what according to experts is the strongest eruption in the past six years. (Photo by Ezequiel Becerra/AFP Photo)

“As a photographer, peregrinator and naturalist, I have been searching for the ultimate unworldly world. I've always been drawn to unusual travel destinations. For me, to lose myself in a different culture is a great way to find balance in my life...”. – Li Xinzhao. (Photo by Li Xinzhao)

These stunning photographs really do show a land of fire and ice! The frozen landscape of the Olkhon Islands, Russia, appears to be ablaze in some of these pictures as the icy sheets of the glaciers reflect the early morning suns rays. (Photo by Vladimir Ryabkov/Caters News Agency)

In this February 1, 2017 photo, environmental activist Maruja Inquilla poses for a photo next to a Municipal waste treatment plant with water that flows into Lake Titicaca, in Juliaca, in the Puno region of Peru. “If the frogs could talk they would say, This is killing me”," said Inquilla, who recently showed up at the Puno governor's house carrying plastic bags filled with hundreds of dead frogs in protest. (Photo by Rodrigo Abd/AP Photo)

Scared of Heights. “Taken from the highest residential building in Asia: the Zenith in Busan. This was taken with official permission (which took me months to get) and safety measures were taken. I had to hang myself over the edge to get this shot. Not for the faint of heart! But when you’re at a height like this, the world below you just seems different. It takes away the fear one would normally have, and gives a sense of peace instead”. (Photo by Albert Dros/NatGeo Cities Travel Photographer of the Year 2017)

“Show us our butts! Mucawana tribe – Angola. In Soba village, the Muhacaona (Mucawana) tribe, perhaps the best place i have visited. They use cow dung and fat to make this so nice haircut, and love the beads. They asked me to make pictures of their backs... and butts to see on the camera screen if everything was perfect!”. (Photo and comments by Eric Lafforgue)