Barren-ground caribou in Denali National Park and Preserve, Alaska, USA (© Design Pics/Danita Delimont)

Grotta della Poesia in Roca, near Lecce, Italy (© Amazing Aerial Agency/Offset by Shutterstock)

Springboks near a waterhole in Etosha National Park, Namibia (© Charlie Summers/Minden Pictures)

Cyclists on a wooden bridge over the river Soča, Triglav National Park, Slovenia (© Amazing Aerial Agency/Offset by Shutterstock)

The Dune of Pilat, Arcachon Bay, France (© aluxum/iStock/Getty Images Plus)

La Selva Biological Station, Costa Rica (© Greg Basco/Minden Pictures)

Sea stacks on the Isle of Lewis, Outer Hebrides, Scotland (© Cody Duncan/Cavan Images)

An indigo bunting on a sunflower (© William Krumpelman/Getty Images)

Jack fish at Cabo Pulmo National Park, Sea of Cortez, Baja California, Mexico (© Christian Vizl/Tandem Stills + Motion)

Nossa Senhora da Graça Fort near Elvas, Portugal (© Luis Pina Photography/Shutterstock)

Annular eclipse over New Mexico, USA, 20 May 2012 (© ssucsy/Getty Images)

Small loch in Glen Etive, Scotland (© Oliver Hellowell/Minden Pictures)

Rio Grande river, Big Bend National Park, Texas, USA (© Ian Shive/Tandem Stills + Motion)

Eurasian brown bear cub, Finland (© Jules Cox/Minden Pictures)

Spirit Island, Maligne Lake, Jasper National Park, Alberta, Canada (© Jeff Penner/EyeEm/Getty Images)

Lake Pinatubo, Zambales, Philippines (© Amazing Aerial Agency/Offset by Shutterstock)

Tamihi Creek, British Columbia, Canada (© Jason Wilde/TANDEM Stills + Motion)

Bright Eye sea cave, Nā Pali Coast, Kauai, Hawaii, USA (© jimkruger/Getty Images)

Chapel Bridge over the river Reuss in Lucerne, Switzerland (© Neleman Initiative/Gallery Stock)

Greater flamingos, India (© Amresh Mishra/500px/Getty Images)

Lavender fields, Oxfordshire, England (© Peter Greenway/EyeEm/Getty Images)

Rothschild's giraffe, Lake Nakuru National Park, Kenya (© Theo Allofs/Minden Pictures)

Seljalandsfoss waterfall, Iceland (© Tom Mackie/plainpicture)

Fireflies in Nichinan, Tottori Prefecture, Japan (© north-tail/Getty Images Plus)

Empress brilliant hummingbird and a bee in Colombia (© Jiri Hrebicek/Alamy)

Portuairk, Ardnamurchan peninsula, Scottish Highlands (© Cavan Images/Offset by Shutterstock)

Kamikōchi, Nagano Prefecture, Japan (© sadao/Shutterstock)

Cittadella, Gozo, Malta (© Davide Seddio/Getty Images)

Anse Source d'Argent, La Digue, Seychelles (© Roland Gerth/eStock Photo)

Cherry blossoms, Queen Elizabeth Park, Vancouver, Canada (© Harris Hui/Getty Images)