The Al-Gaffal is an annual long-distance race between crews sailing 60-ft. traditional wooden boats called dhows and takes place in the Persian Gulf, between the island of Sir Bu Nair, near the Iranian coast and the Gulf emirate of Dubai. Photo: Traditional wooden boats, or dhows, compete at sunrise during the Al Gaffal race, a long-distance dhow sailing race, near Sir Bu Nuayr, near Sharjah May 18, 2014. (Photo by Martin Dokoupil/Reuters)

Actors perform the living Nativity biblical scenes in Postojna cave in Postojna, Slovenia, December 22, 2015. (Photo by Srdjan Zivulovic/Reuters)

Beneath the Swedish capital lies an intricate web of underground train lines. More than 90 of the 100 stations in the 110km tunnel system, sometimes referred to as “the world’s longest art gallery”, have been decorated with paintings, installations, mosaics and sculptures by 150 artists since the 1950s. After spending a couple of weeks exploring arctic Norway and Sweden, London-based travel photographer Conor MacNeill headed underground to capture images of the metro stations. Here: A rainbow arcs over a girl on the platform of Stadion station. (Photo by Conor MacNeill/The Observer)

In this June 29, 2018 photo, a wild horse shakes off dust near a watering hole outside Salt Lake City. Harsh drought conditions in parts of the American West are pushing wild horses to the brink and forcing extreme measures to protect them. (Photo by Rick Bowmer/AP Photo)

A cave diver in Anhumas Abyss, Bonito, Brazil. (Photo by Marcio Cabral/Epson International Pano Awards 2018)

A British Airways passenger plane flies in front of the moon above London, Britain, May 3, 2018. (Photo by Toby Melville/Reuters)

Actors dressed as a “Yeti” attend a promotional event for Travel Channel's “Expedition Unknown: Hunt for the Yeti” in Manhattan, New York City, U.S., October 4, 2016. (Photo by Brendan McDermid/Reuters)

Kevin and Merith Starren have their picture taken by Merith's brother Mark Ernst (R) and nephew Logan Ernst (L) in front of a 50-foot snowman named “Granddaddy” in Gilman, Minnesota, March 6, 2014. (Photo by Eric Miller/Reuters)