Bison grazing at thermal hot springs, Yellowstone National Park, Wyoming, United States (© Cheryl Ramalho/Getty Images)

Colourful maple leaves and bamboo forest in Arashiyama, Kyoto, Japan (© DoctorEgg/Getty Images)

Jellyfish swimming in the Pacific, Guerrero, Mexico (© Christian Vizl/TANDEM Stills + Motion)

Tower Bridge, London, England (© Nick Brundle Photography/Getty Images)

Peña Roya beech forest, Moncayo Natural Park, Zaragoza, Aragon, Spain (© David Santiago Garcia/DEEPOL by plainpicture)

Colourful lanterns at the temple of Wat Phra That Hariphunchai, Lamphun, Thailand (© MR. ANUJAK JAIMOOK/Getty Images)

Polar bear in Churchill, Manitoba, Canada (© karen crewe/Getty Images)

Interstellar clouds in the Lagoon Nebula, captured by the Hubble Space Telescope (© ESA/NASA)

Black-tailed prairie dogs at Roberts Prairie Dog Town, Badlands National Park, South Dakota, United States (© Greg Vaughn/Getty Images)

The Externsteine rock formation in the Teutoburg Forest, Germany (© Michael Sroka/Getty Images)

Aerial view of the Colosseum, Rome, Italy (© Nico De Pasquale Photography/Getty Images)

Quiver trees at night with the Milky Way, Keetmanshoop, Namibia (© Wim van den Heever/naturepl.com)

Mother manatee and calf, Crystal River, Florida, United States (© Gregory Sweeney/Getty Images)

Irohazaka RoadTochigi, Japan (© oneinchpunch/Shutterstock)

A traboule in Lyon, France (© TPopova/Getty Images)

Shenandoah National Park, Virginia, United States (© Michael Ver Sprill/Getty Images)

Male hooded merganser, Oregon, United States (© Eric Vogt/TANDEM Stills + Motion)

Hungarian Parliament Building, Budapest, Hungary (© Alexander Spatari/Getty Images)

Chapada Diamantina, Bahia, Brazil (© Marcio Dufranc/Getty Images)

Harbour seals at Robert Moses State Park, Long Island, New York, United States (© Vicki Jauron, Babylon and Beyond Photography/Getty Images)

Monte Sirente, Abruzzo, Italy (© ValerioMei/Getty Images)

Ammonite fossil from Madagascar (© ThomasLENNE/Shutterstock)

Gwalior Fort, Madhya Pradesh, India (© ImagesofIndia/Shutterstock)

The Trevi Fountain in Rome, Italy (© Nico De Pasquale Photography/Getty Images)

Olive orchard in the Serra de Tramuntana, Mallorca, Balearic Islands, Spain (© cinoby/Getty Images)

Eastbourne Pier, East Sussex, England (© Tolga_TEZCAN/Getty Images)

Val Brandet, Brescia, Lombardy, Italy (© ClickAlps/Alamy)

Red deer stag in De Hoge Veluwe National Park, Netherlands (© CreativeNature_nl/Getty Images)

Christmas market in Leipzig, Germany (© Krzysztof Baranowski/Getty Images)