The aurora borealis over Spirit Island on Maligne Lake, Jasper National Park, Canada (© Mumemories/Getty Images)

Eucalyptus trees, Megalong Valley, Blue Mountains National Park, NSW, Australia (© Andrew Peacock/TANDEM Stills + Motion)

Southern yellow-billed hornbills in Kruger National Park, South Africa (© Richard Du Toit/Minden Pictures)

Aerial view of Khao Sok National Park, Surat Thani, Thailand (© Peetatham Kongkapech/Getty Images)

Desert bighorn sheep in Valley of Fire State Park, Nevada, United States (© Rachid Dahnoun/Cavan Images)

Plum blossoms, China (© zhikun sun/Getty Images)

Schleswig-Holstein Wadden Sea National Park, Germany (© 3quarks/Getty Images)

St Mark's Clock Tower, Venice, Italy (© scaliger/Getty Images)

A lion sleeping in Ishasha Sector, Queen Elizabeth National Park, Uganda (© Gunter Nuyts/Getty Images)

Broken Beach in Nusa Penida, Bali, Indonesia (© joakimbkk/Getty Images)

Château de Sully-sur-Loire, Centre-Val de Loire, France (© StockPhotoAstur/Shutterstock)

Gran Paradiso National Park, Piedmont, Italy (© Stefano Zaccaria/Alamy)

Dolmen of Sorginetxe, Basque Country, Alava, Spain (© David Herraez Calzada/plainpicture)

The Temple of Saturn in the Roman Forum, Rome, Italy (© Nico De Pasquale Photography/Getty Images)

A kingfisher perched on a branch (© NJphoto/Alamy)

Samuel Beckett Bridge, Dublin, Ireland (© Colm Keating/Tandem Stills + Motion)

Red rock formations, Sedona, Arizona, United States (© Jim Ekstrand/Alamy Stock Photo)

Black heron canopy hunting, Chobe National Park, Botswana (© Paul Souders/Minden PIctures)

Daffodils glow in the morning (© LedyX/Shutterstock)

Mist over lowland rainforest, Danum Valley, Sabah, Borneo, Malaysia (© Nick Garbutt/Alamy)

Water lilies at the surface of Cenote Nicte-Ha, Tulum, Mexico (© Franco Banfi/NPL/Minden)

Lightning and storm clouds at sunset near Bowman, Nebraska, United States (© john finney photography/Getty Images)

Desert elephant with calf feeding on tall grass, Namibia (© Christophe Courteau/Minden Pictures)

European goldfinches in a sunflower field, Germany (© Juniors Bildarchiv GmbH/Alamy)

Manatee in Crystal River, Florida, United States (© Stephen Frink/Getty Images)

Odeon of Herodes Atticus theatre, Acropolis of Athens, Greece (© f11photo/Getty Images)

Female black-naped monarch nesting (© komkrit tonusin/Alamy)

Superbloom in Carrizo Plain National Monument, California, United States (© Robb Hirsch/TANDEM Stills + Motion)

Aerial view of Sydney Harbour, New South Wales, Australia (© jamenpercy/Getty Images)

Ostuni at dusk, Apulia, Italy (© Feng Wei Photography/Getty Images)