A treetop walkway in the Bavarian Forest National Park, Neuschönau, Germany (© imageBROKER/Alamy)

Solar eclipse sequence from 21 August 2017 (© Lindsay Daniels/Tandem Stills + Motion)

The Transfăgărășan in Transylvania, Romania (© Calin Stan/Shutterstock)

Salcombe harbour on the south coast of Devon (© Devon and Cornwall Photography/Getty Images)

Peel Castle on St Patrick’s Isle, Isle of Man (© Massimo Ripani/SIME/eStock Photo)

Rainbow-coloured balloons at the Pride in London parade (© darko m/Shutterstock)

Peloton during the 2018 Tour de France in Valence, France (© Justin Setterfield/Getty Images)

Blue walls of Chefchaouen, Morocco (© Tatsuya Ohinata/Getty Images)

Jaguar in the Pantanal wetlands, Brazil (© Andy Rouse/Minden Pictures)

Visitors on El Caminito del Rey in the province of Málaga, Spain (© Ken Welsh/Alamy)

Artificial light from Earth (© NASA)

Waterperry Gardens in Oxfordshire (© Lauren Hibbit/Danita Delimont)

Sailors begin their journey from Chicago to Mackinac Island, Michigan, USA, during the Race to Mackinac (© Karen I. Hirsch/Alamy)

Action from the 1950 British Grand Prix at Silverstone (© Klemantaski Collection/Hulton Archive/Getty Images)

Mount Fuji and twin rocks (Ushitukiiwa) in Matsuzaki, Japan (© Tommy Tsutsui/Getty Images)

The Ernest Hemingway Home and Museum in Key West, Florida, USA (© Werner Bertsch/eStock Photo)

A flock of sheep in the Gobi Desert (© Patrick Baz/Getty Images)

Leatherback sea turtles in Trinidad and Tobago (© Shane P. White/Minden Pictures)

Garden of the Gods Park in Colorado Springs, Colorado, USA (© lightphoto/iStock/Getty Images)

Artist Luke Jerram's installation 'Museum of the Moon' at Liverpool Cathedral (© Christopher Furlong/Getty Images)

Buckingham Palace and Victoria Memorial for Queen Victoria's bicentennial year (© CTC Creative/Offset)

Hummingbird hawk-moth feeding on flower, Sardinia, Italy (© patriziomartorana/iStock/Getty Images Plus)

The Skywalk on the Rock of Gibraltar (© Stephen Ball/Alamy)

Meerkats in the Kalahari Desert in Botswana (© Aluma Images/Getty Images)

Jane's Carousel in Brooklyn, New York, USA (© Grzegorz Gill/Shutterstock)

Alphorn musicians perform during the International Alphorn Festival in Nendaz, Switzerland (© Fabrice Coffrini/Getty Images)

The shoreline of Gandoca-Manzanillo Wildlife Refuge, in Costa Rica (© Greg Basco/Minden Pictures)

Carhenge, created by Jim Reinders, in Nebraska, USA (© Charlie Summers/Minden Pictures)

Puffins among sea campion on Skomer Island, Pembrokeshire, Wales (© Ross Hoddinott/Minden Pictures)

Giant tortoises on Alcedo Volcano in the Galápagos Islands (© Tui De Roy/Minden Pictures)

The Dew Stone, part of the Stanza Stones trail, in Yorkshire (© Rebecca Cole/Alamy)