“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

The feet of a Filipino penitent is nailed to a wooden cross during Good Friday rituals on April 3, 2015 at Cutud, Pampanga province, northern Philippines. Several Filipino devotees had themselves nailed to crosses Friday to remember Jesus Christ's suffering and death, an annual rite frowned upon by church leaders in this predominantly Roman Catholic country. (Photo by Aaron Favila/AP Photo)

Performers take part in a rain soaked Notting Hill Carnival on August 25th, 2014 in London, England. Despite the bad weather over 1 million visitors are expected to attend the two-day event which is the largest of its kind in Europe. The event has taken place on the West London streets every August Bank Holiday weekend since 1964. (Photo by Mary Turner/Getty Images)

Stunning images have revealed ice-cool British tourists chilling out inside Europe’s largest glacier – despite being at risk of flooding. The spectacular collection of images show the explorers braving the freezing temperatures to climb, photograph and even abseil down the inside of the icy cliff sides. Another image shows one visitor on his knees appearing to pray next to a water fall of melted ice. Other glistening shots show an adventurer trying to keep warm by a fire whose flames dance beautifully against the glossy roof. (Photo by Einar Runar Sigurdsson/Mediadrumworld.com)

An undated handout picture made available by the Symbio Wildlife Park on 28 November 2016 shows three Pygmy Marmoset monkeys including an adult male, a female juvenile and a four-week-old baby, at the Symbio Wildlife Park in Helensburgh, South of Sydney, New South Wales, Australia. (Photo by EPA/Symbio Wildlife Park)

The ferocity of crises worldwide is forcing a record number of people to flee their homes, seeking some form of safety within their own country or across international borders. There are 65.3 million displaced people worldwide, including 21.3 million refugees. Most have lost their homes to armed conflict or natural disasters but other factors, such as extreme poverty and climate change, also drive displacement. The International Organisation for Migration commissioned photojournalist Muse Mohammed to document the plight of the displaced. (Photo by Muse Mohammed/IOM)

Meanwhile, over on Portobello beach, members of the Upsala circus take a stroll before their fringe debut, Ping-Pong Ball Effect in Edinburgh, England on August 1, 2017. (Photo by Murdo Macleod/The Guardian)

Indian Air Force personnel parade during the 85th Air Force Day celebrations at Hindon Air Force base in Ghaziabad on October 8, 2017. (Photo by AFP Photo/Stringer)