A Ukrainian serviceman fires a 2S7 Pion self-propelled gun during military exercises near the village of Divychky in Kiev region, Ukraine, October 21, 2016. (Photo by Valentyn Ogirenko/Reuters)

Only 156 people remained in the tribe when Jan visited in Accham District, Nepal, January 2016. Hidden deep in the Himalayan forest is one of the world’s last enduring nomadic tribes who are resisting attempts to move them into permanent settlements. (Photo by Jan Moller Hansen/Barcroft Images)

Indonesian tourists take a selfie as Mount Bromo spews volcanic material and ash into the air during an eruption in Probolinggo, East Java, Indonesia, 31 December 2015. Indonesia's Mount Bromo is on the second highest alert level as its activity has increased in the last two months. (Photo by Fully Handoko/EPA)

Galapagos – Rocking the Cradle: Four major ocean currents converge along the Galapagos archipelago, creating the conditions for an extraordinary diversity of animal life, April 25, 2016. The islands are home to at least 7,000 flora and fauna species, of which 97 percent of the reptiles, 80 percent of the land birds, 50 percent of the insects and 30 percent of the plants are endemic. (Photo by Thomas P. Peschak for National Geographic/World Press Photo)

Winners of a competition enjoy a meal 450ft up on the roof of a central London skyscraper on August 21, 2018, as Deliveroo recreates “Lunch Atop a Skyscraper”, the photograph taken during the construction of the Rockefeller Center in New York City, 1932. (Photo by Jonathan Brady/PA Images via Getty Images)

A couple joke as they walk on the beach on August 22, 2018 in Wonsan, North Korea. (Photo by Carl Court/Getty Images)

A peformance artist attends an election rally for Cameroon presidential candidate for the opposition Univers party, Cabral Libii in Yaounde, Cameroon 06 October 2018. Africa's oldest president Paul Biya who has been in power since 1982 is up against eight candidates when voters go to the polls 07 October 2018. 6.9 million registered voters will head to the polls but marginalised anglophone separatists in the North West and South West of the country threaten to disrupt the elections. (Photo by Nic Bothma/EPA/EFE)

A Mongolian Bloody Mary, made with pickled sheep eyeballs and tomato juice, is displayed at the Disgusting Food Museum in Malmo, Sweden November 1, 2018. (Photo by Mikael Nilsson/Reuters)