Newborn brown-throated sloth with mother, Sloth Sanctuary of Costa Rica (© Suzi Eszterhas/Minden Pictures)

Books by Hans Christian Andersen (© radiokafka/Adobe Stock)

Milky Way over the Bisti/De-Na-Zin Wilderness in New Mexico, USA (© Cory Marshall/Tandem Stills + Motion)

For Earth Month, a symmetrical forest known as a Nelder plot (© Rachid Dahnoun/Tandem Stills + Motion)

Blossoming cherry trees at a tea plantation in Longyan, China (© VCG/Getty Images)

Sunbeams across Tartu County, Estonia (© Sven Zacek/Minden Pictures)

For International Beaver Day, a beaver swimming in Grand Teton National Park, Wyoming, USA (© Charlie Hamilton James/Getty Images)

The National Wallace Monument overlooking Stirling in Scotland (© Elena Korchenko/age fotostock)

Bioluminescent algae along the shores of the Matsu Islands off the coast of Taiwan (© Wan Ru Chen/Getty Images)

A spiral staircase in Hamburg, Germany (© Rüdiger Hess/geo-select FotoArt)

Dutch tulip fields in the Duin- en Bollenstreek region for the Amsterdam Tulip Festival (© Frans Sellies/Getty Images)

The Mount Washington Observatory in New Hampshire, USA (© Mike Theiss/Getty Images)

Vinyl records in Rosmalen, the Netherlands (© DutchScenery/Shutterstock)

Dubai Miracle Garden, United Arab Emirates (© Amazing Aerial/Offset)

Path to San Juan de Gaztelugatxe, Basque Country, Spain, for the new season of Game of Thrones (© Anton Petrus/Moment/Getty Images)

Bauhaus Archive Museum of Design in Berlin, Germany (© Juergen Henkelmann Photography/Alamy)

Hope Valley in the Peak District (© Daniel_Kay/Getty Images Plus)

Tŵr Mawr lighthouse on Llanddwyn Island in Anglesey, North Wales (© Jon Arnold/DanitaDelimont.com)

Paepalanthus flowers at sunset, Chapada dos Veadeiros National Park, Brazil (© Marcio Cabral/Getty Images)

The Cove of Spires in Kenai Fjords National Park near Seward, Alaska, USA (© Grant Ordelheide/Tandem Stills + Motion)

A rabbit in the grass for Easter (© wisan224/Getty Images Plus)

Laysan albatross chick on Midway Atoll, Northwestern Hawaiian Islands (© Jaymi Heimbuch/Minden Pictures)

Painted relief of St George and the Dragon at Lincoln Cathedral (© Michael Foley/Alamy)

The Quinault Rainforest in Olympic National Park, Washington State, USA (© Jason Savage/Tandem Stills + Motion)

Ice cave at sunset in Vatnajökull, Iceland (© Johnathan Ampersand Esper/Aurora Photos)

Ruff male displaying on Varanger Peninsula in Norway (© Winfried Wisniewski/Minden Pictures)

Mexican giant cardon cactus (© Ed Reardon/Alamy)

Prairie and pinnacles near Castle Trail in Badlands National Park, South Dakota, USA (© Danita Delimont/Getty Images)

Wisteria blooms at Kawachi Fuji Gardens in Kitakyushu, Japan (© Wibowo Rusli/Alamy)

Louis Armstrong performs with bandmates in Vienna, Austria, on 22 February 1959 (© Franz Hubmann/Getty Images)