Green sea turtle diving, Great Barrier Reef, Queensland, Australia (© imageBROKER/Alamy)

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

Aerial view of cyclists on a wooden suspension bridge over the river Soča in Slovenia (© Amazing Aerial Agency/Offset by Shutterstock)

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

Black-mandibled toucan in the rainforest canopy of La Selva Biological Station in Costa Rica (© Greg Basco/Minden Pictures)

Black-mandibled toucan in the rainforest canopy of La Selva Biological Station in Costa Rica (© Greg Basco/Minden Pictures)

Mulberry harbour at Arromanches-les-Bains, Normandy, France (© agefotostock/Alamy)

Thousands of jack fish swimming together 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, on 20 May 2012 (© ssucsy/Getty Images)

Waterfall at Pöllat Gorge near Neuschwanstein Castle, Bavaria, Germany (© Gary Whitton/Alamy)

View of the Rio Grande River in Big Bend National Park, Texas, USA (© Ian Shive/Tandem Stills + Motion)

Eurasian brown bear cub in the taiga forest, Finland (© Jules Cox/Minden Pictures)

Lavender fields at lavender farm, Islip, Chipping Norton, Oxfordshire (© Peter Greenway/EyeEm/Getty Images)

Aerial view of volcanic Lake Pinatubo and mountains, Porac, Philippines (© Amazing Aerial Agency/Offset by Shutterstock)

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

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

People surfing at Burleigh Heads, Gold Coast, Australia (© Vicki Smith/Getty Images)

Bald eagle pair with a chick in their nest near the Yukon River, Yukon, Canada (© Mark Newman/Minden Pictures)

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

Reading the news aboard the Empire Windrush on arrival at Tilbury, Essex on 22 June 1948 (© Hulton-Deutsch Collection/CORBIS/Corbis via Getty Images)

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

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

View of the midnight sun behind Seljalandsfoss waterfall near the south coast of Iceland (© Tom Mackie/plainpicture)

Glass sightseeing platform in Shilinxia Scenic Area, Pinggu District of Beijing, China (© STR/AFP via Getty Images)

Rainbow balloons for Pride Month (© lazyllama/Shutterstock)

Order of Play boards on Centre Court at the All England Lawn Tennis Club, Wimbledon, London (© AELTC/Bob Martin via USA TODAY Sports)

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

Manicouagan Crater in Québec, Canada (© Universal History Archive/Universal Images Group via Getty Images)

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