“Red Arrows” at the 2016 royal air tattoo, RAF Fairford, UK. By Jonny Williams, finalist: action. (Photo by Jonny Williams/UK National Geographic Traveller Photography Competition 2018)

Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

In this Sunday, March 11, 2017 photo, children fight in a boxing ring in Chitungwiza, Zimbabwe. Zimbabwean boys as young as 10 hurry every weekend to a boxing ring whose nickname, Wafa Wafa, in the local Shona language suggests that whoever enters will be lucky to come out alive. (Photo by Tsvangirayi Mukwazhi/AP Photo)

Food is placed on the tomb of pet dog Xixi at Baifu pet cemetery ahead of the Qingming Festival on the outskirts of Beijing, China March 26, 2016. The Chinese characters on the gravestone read: “Mommy's only good son”. (Photo by Jason Lee/Reuters)

A young Afghan vendor waits for customers to buy sheep's heads at a roadside stall at the busy market in Kabul on November 29, 2015. (Photo by Wakil Kohsar/AFP Photo)

“The Carnival Triumph finally made port on Thursday night, after what should have been an idyllic four-day cruise turned into a grueling week-long ordeal for more than 3,000 passengers and 1,000 crew. Some kissed the ground as they disembarked the ship, while others swore never to go on another cruise again. Many spoke of the well-documented unsanitary conditions on board the 272-metre Triumph, which lost power in the Gulf of Mexico on Sunday”. – Tom Dart and Adam Gabbatt via Guardian

Photo: Kendall Jenkins of Houston kisses the ground after stepping off the Carnival ship Triumph (Photo by AP Photo)

Three young women preparing a guy. They are sitting him on a keg labelled “gun powder”. (Photo by Fox Photos/Getty Images). 1929

Leaves and forest foliage claim abandoned motors at makeshift car graveyards. German photographer Dieter Klein travels the world to find vintage automobiles left to rust in leafy forests and fields. Here: Seemingly camouflaged cars are stacked on top of each other causing them to blend in with the landscape, in 2013, France. (Photo by Dieter Klein/Barcroft Media)