Željava Air Base, situated on the border between Croatia and Bosnia and Herzegovina under Plješevica Mountain, near the city of Bihać, Bosnia, was the largest underground airport and military air base in the former Yugoslavia, and one of the largest in Europe. (Photo by Thomas Windisch/Exclusivepix Media)

In this photo taken April 15, 2015, Clay Hielscher of Overbrook, Kan., poses for a photo in his home made Iron Man suit. While he enjoys building the battlesuits of his favorite super hero, Hielscher said the real reason he is so passionate about his pastime is his 11-year-old daughter, Kyrianna. They design and construct the suits together. (Photo by Chris Neal/AP Photo/The Topeka Capital-Journal)

An Ambassador car, licensed as taxi rolls past other vehicles through a busy road in Kolkata, india, Monday, May 26, 2014. India's oldest car factory has abruptly suspended production of the hulking Ambassador sedan that has a nearly seven-decade history as the car of the Indian elite. (Photo by Bikas Das/AP Photo)

This artist's scoreboard displays a fictional game between Mars and Earth, with Mars in the lead. It refers to the success rate of sending missions to Mars, both as orbiters and landers. Of the previous 39 missions targeted for Mars from around the world, 15 have been successes and 24 failures. For baseball fans, that's a batting average of .385. The United States has had 13 successes out of 18 attempts, or a “batting average” of .722. NASA's Curiosity rover, set to land on the Red Planet the evening of Aug. 5, 2012 PDT (morning of Aug. 6 EDT), will mark the United States' 19th attempt to tackle the challenge of Mars, and the world's 40th attempt. (Image by NASA/JPL-Caltech)

A model presents a creation from Dominnico's Autumn – Winter 2020 / 2021 collection during the Mercedes Benz Fashion Week in Madrid on January 31, 2020. (Photo by Gabriel Bouys/AFP Photo)

Nick Krist makes a funny face as he and his son, Noah, 8, take a selfie before a baseball game between the Los Angeles Angels and the Minnesota Twins, Wednesday, July 22, 2015, in Anaheim, Calif. (Photo by Jae C. Hong/AP Photo)

Competitors release their hens during the World Championship Hen Racing Championships in Bonsall, Britain August 1, 2015. (Photo by Darren Staples/Reuters)

The British and Irish Association of Zoos and Aquariums (BIAZA) has announced the winning images in its annual photography competition. The 2020 winners show the important work of zoos and aquariums at an immensely challenging time. After months of closures, these conservation organisations are reeling from the financial impacts of the coronavirus pandemic. Here: Runner-up, Heart and Minds: Nifty nose, by Samantha Allworthy at Longleat. Species: prehensile tailed porcupines. (Photo by Samantha Allworthy/BIAZA 2020 Photography Competition)