The Roman Forum, Rome, Italy (© Peter Zelei Images/Getty Images)

Moonlight and the Milky Way over Mount Rainier in Mount Rainier National Park, Washington (© Brad Goldpaint/Cavan)

Greater one-horned rhinoceros in Kaziranga National Park, Assam, India (© Robert Harding World Imagery/Shutterstock)

The National Aquatics Center in Beijing, China (© Han Haidan/China News Service via Getty Images)

The island of Mont-Saint-Michel in Normandy, France (© DaLiu/Getty Images)

Peacock at Nagarahole National Park in Karnataka, India (© Vivek BR/Shutterstock)

Lake Tekapo with Aoraki/Mount Cook National Park in the background on New Zealand's South Island (© Sophie Dover/Getty Images)

Lake Tekapo, South Island, New Zealand (© Sophie Dover/Getty Images)

The 'Flower of Life' symbol drawn in the snow by artist Michael Uy, Jacobsdorf, Brandenburg, Germany (© Patrick Pleul/picture alliance via Getty Images)

Ponte Vecchio bridge near Bobbio, Italy (© afinocchiaro/Getty Images)

Ponte Vecchio bridge, Bobbio, Italy (© afinocchiaro/Getty Images)

The ancient architecture of temples on Hemakuta Hill in Hampi, India (© Images of India/Alamy Stock Photo)

A European hare jumps through a wetland in the Netherlands (© Jim Brandenburg/Minden Pictures)

Lanyon Quoit burial chamber, Cornwall, England (© Guy Edwardes/Minden Pictures)

Giant panda in Wolong National Nature Reserve, Sichuan, China (© Katherine Feng/Minden Pictures)

Coastal redwoods and wood sorrel, Prairie Creek Redwoods State Park, California (© Jack Dykinga/Minden Pictures)

Multicoloured powders for sale during Holi (© Nuno Valadas/Getty Images)

Chicagohenge sunset, Chicago, Illinois (© Razvan Sera/Amazing Aerial Agency)

Chicago, Illinois, USA (© Razvan Sera/Amazing Aerial Agency)

Holy Trinity Church, Stratford-upon-Avon, England (© James Osmond/Getty Images)

Waterfall in Thousand Springs State Park, Hagerman Valley, Idaho (© knowlesgallery/Getty Images)

Grand Canyon National Park during a thunderstorm, Arizona (© spkeelin/Getty Images)

Victoria Memorial with adjoining garden and lake in Kolkata, India (© Roop_Dey/Shutterstock)

Red squirrels in a nest of lichen and pine needles, Scottish Highlands (© Neil Anderson/Minden Pictures)

Great tit and yellow crocuses (© Nataba/Getty Images)

Great tit and yellow crocuses (© Nataba/Getty Images)

Swan and her cygnets on a nest in Stroud, Gloucestershire (© PJ photography/Shutterstock)

Caribbean coast near Buritaca, Colombia (© Nicholas Hills/Getty Images)

Caribbean coast near Parque Nacional Natural Tayrona, Colombia (© Nicholas Hills/Getty Images)

Eiffel Tower in Paris, France (© Susanne Kremer/eStock Photo)

'Greetings From Giza' by Jean Rene, in Cairo, Egypt (© Ammar ABD RABBO/Abaca Press/Alamy)