Conwy Castle illuminated at night, Conwy (© Jon Arnold/DanitaDelimont.com)(Bing United Kingdom)

Saguaro cactus flowers, Coronado National Forest, Arizona, USA (© Jack Dykinga/Minden Pictures)(Bing United Kingdom)

Spectral tarsiers in a ficus tree in Tangkoko Batuangus Nature Reserve, Indonesia (© Ondrej Prosicky/Shutterstock)(Bing United Kingdom)

Divers at El Pit Cenote, located in Dos Ojos Natural Park, Quintana Roo, Mexico (© Christia Vizl/Tandem Stills + Motion)(Bing United Kingdom)

Fairy chimneys and cave dwellings in Uçhisar, Cappadocia, Turkey (© Ivan Kmit/Alamy)(Bing United Kingdom)

Male mountain bluebird in Yellowstone National Park, Wyoming, USA (© Jason Savage/Tandem Stills + Motion)(Bing United Kingdom)

Muir Woods National Monument, California, USA (© Mia2you/Shutterstock)(Bing United Kingdom)

The catalogue and enquiries stall at the Women's Exhibition, London, May 1909. (© Museum of London/Heritage Images/Getty Images)(Bing United Kingdom)

Flowing clouds over the Atlantic Ocean and Tenerife mountains, Canary Islands, Spain (© MikeMareen/iStock/Getty Images Plus)(Bing United Kingdom)

Bird's-eye view of Bronte Baths ocean pool outside Sydney, Australia (© Shay Cooper/Media Drum World/Cavan Images)(Bing United Kingdom)

Polar bear cubs looking out of their den in Wapusk National Park in Manitoba, Canada (© Robert Harding/Alamy)(Bing United Kingdom)

Aerial view of Superkilen Park in Norrebro district in Copenhagen, Denmark (© Oliver Förstner/Alamy)(Bing United Kingdom)

Loughrigg Tarn sunrise, Ambleside, Lake District (© John Finney photography/Getty Images)(Bing United Kingdom)

The Circle Bridge in Copenhagen, Denmark (© Lingxiao Xie/Getty Images)(Bing United Kingdom)

Blooming cherry trees in Jerte Valley, Province of Cáceres, Spain (© Westend61/Getty Images)(Bing United Kingdom)

Shakespeare's handwriting from the play Sir Thomas More, British Library, London (© British Library/Alamy)(Bing United Kingdom)

Knowth burial mound in Newgrange, Boyne Valley, Ireland for St Patrick's Day (© whatapicture/plainpicture)(Bing United Kingdom)

Nasa astronaut works on the International Space Station during a spacewalk in 2006 (© NASA)(Bing United Kingdom)

A heron perches on a piling at the Salton Sea in California, USA (© Garret Suhrie/Cavan Images)(Bing United Kingdom)

Sunrise at Angkor Wat in Cambodia (© Sergio Diaz/Getty Images)(Bing United Kingdom)

Women climbing a stepwell near Amber Fort in Jaipur, Rajasthan, India (© Shanna Baker/Offset)(Bing United Kingdom)

Mother owl dotes on her newborn son at their farmyard abode (© Cavan Images/Media Drum World/Laura Dyer)(Bing United Kingdom)

Lenticular clouds over Mount Rainier, Washington, USA (© Delrious/Shutterstock)(Bing United Kingdom)

European bee-eaters in the Extremadura region of Spain (© Martin Demmel/Offset)(Bing United Kingdom)

The Radcliffe Camera, Oxford for Tolkien Reading Day (© Joe Daniel Price/Getty Images)(Bing United Kingdom)

Aerial view of the Big Sur coastline near Monterey, California, USA (© Blue Planet Archive/Alamy)(Bing United Kingdom)

Carrick-a-Rede rope bridge connecting two cliffs near Ballintoy, County Antrim, Northern Ireland (© NordicMoonlight/iStock/Getty Images Plus)(Bing United Kingdom)

Orgues d'Ille-sur-Têt, Eastern Pyrenees, France (© SFL Choice/Alamy Stock Photo)(Bing United Kingdom)

Leopard snoozing in a tree in Namibia (© M. Watsonantheo/SuperStock)(Bing United Kingdom)

A European crested tit weathers a storm in Scotland (© Ben Hall/Minden Pictures)(Bing United Kingdom)

The Twist bridges the Randselva River, at the Kistefos Museum's sculpture park in Norway (© Laurian Ghinitoiu)(Bing United Kingdom)