A member of the United States Naval Academy freshman class crawls through trenches at the wet and sandy station during the annual Sea Trials training exercise at the U.S. Naval Academy on May 13, 2014 in Annapolis, Maryland. For 14 hours, the United States Naval Academy freshman class, also known as Plebes, worked as a team to complete many grueling physical and mental challenges that help prepare them for real-world experiences and reinforce leadership, bonds, trust, and teamwork. Of the challenges, they endured: a two-mile regimental run, ground fights, water tactics, aquatics challenges, and survival skills, amongst many others. (Photo by Patrick Smith/Getty Images)

Marines finish a 10 kilometer training hike carrying 55 pound (25 kg) packs during Marine Combat Training (MCT) on February 22, 2013 at Camp Lejeune, North Carolina. Since 1988 all non-infantry enlisted male Marines have been required to complete 29 days of basic combat skills training at MCT after graduating from boot camp. MCT has been required for all enlisted female Marines since 1997. About six percent of enlisted Marines are female. (Photo by Scott Olson/AFP Photo)

Aerial photography platform SkyPixel received 27,000 entries to its 2016 competition. Here are the winning shots plus some of our favourites. Here: Dam near perfect. Second prize in the same category was of the Huia Dam in Auckland, New Zealand. Hong Kong-based SkyPixel was launched in 2014. (Photo by Brendon Dixon/SkyPixel)

An empty beer bottle stands in front of the buildings of the banking district in Frankfurt, Germany, Friday, May 21, 2021. All people gathering on the square for drinks and food left when the police started checking if they are abiding by the coronavirus restrictions. (Photo by Michael Probst/AP Photo)

A huge atlas moth, with a wingspan of more than 9in, photographed on an areca nut plantation in Sirsi, India. (Photo by Uday Hegde/Close Up Photographer of the Year)

These images are enough to make viewers do a double-take. Although they look like vibrant works of abstract art, they are actually drone photographs taken by brothers J.P. and Mike Andrews, from near Wolverhampton, England. Here: Kickflip. (Photo by J.P. Andrews/Mike Andrews/Caters News Agency)

Winner. “I took this vertical image in the Quarry Bay district of Hong Kong during the dusk ‘blue hour’, when there was a perfect balance between the ambient light in the sky and the artificial lights of the high-rise residential buildings”. (Photo by Jatinder Heer/The Guardian)

Runner-up. “The City of London, looking towards the Royal Exchange and the Bank of England. The ever-changing London skyline provides many excellent opportunities for cityscape photography, none more exciting than the ebb and flow of traffic at night”. (Photo by Mark Caldon/The Guardian)