The Ivishak River, Alaska, USA (© Don Paulson/Danita Delimont)

The Roman amphitheatre of Itálica near Santiponce, Spain (© Amazing Aerial Agency/Offset by Shutterstock)

Andromeda galaxy (© NASA/JPL-Caltech)

Dallas Divide in south-west Colorado, USA (© Ronda Kimbrow/Shutterstock)

Huay Mae Khamin waterfall in Khuean Srinagarindra National Park, Thailand (© Casper1774Studio/Getty Images)

Common octopus in sea grass in the Gulf of Lion in the Mediterranean Sea (© BIOSPHOTO/Alamy)

Sandhill cranes and mallard ducks, Bosque del Apache National Wildlife Refuge, New Mexico, USA (© Cathy & Gordon Illg/Jaynes Gallery/DanitaDelimont.com)

Rainbow abalone shell, New Zealand (© Lynda Harper/Minden Pictures)

Low angle view of Rame Head, Cornwall. (© Cavan Images/Offset)

Wapizagonke Lake, La Mauricie National Park, Quebec, Canada (© Instants/Getty Images)

An ichthyosaur fossil of the Jurassic period, Dinosaurland Fossil Museum, Lyme Regis, Dorset (© Christopher Jones/Alamy)

Saguaro 'family' and Milky Way, Saguaro National Park, Arizona, USA (© Christian Foto Az/Shutterstock)

Saguaro 'family' and Milky Way, Saguaro National Park, Arizona (© Christian Foto Az/Shutterstock)

Aerial view of the Temple of Hatshepsut near Luxor, Egypt (© Ratnakorn Piyasirisorost/Moment/Getty Images)

Aerial view of the Temple of Hatshepsut near Luxor, Egypt (© Ratnakorn Piyasirisorost/Moment/Getty Images)

Capel Curig in Snowdonia National Park (© Sebastian Wasek/Sime/eStock Photo)

The Fanal Forest on Madeira Island, Portugal (© Val Thoermer/Alamy)

Fanal forest, Madeira island, Portugal (© Val Thoermer/Alamy)

Otter (Lutra Lutra) in seaweed, Ardnamurchan. (© Michael Durham/Minden Pictures)

Atchafalaya Basin, Louisiana, USA (© Chris Moore/Exploring Light Photography/Tandem Stills + Motion)

Eurasian scops owl in Bohemian Switzerland National Park, Czech Republic (© Milan Zygmunt/Alamy)

Bavljenac Island, Croatia (© Julien Duval/Amazing Aerial Agency)

Bavljenac island, Croatia (© Julien Duval/Amazing Aerial Agency)

Red fox in the Black Forest, Baden-Württemberg, Germany (© Klaus Echle/Minden Pictures)

Red fox, Black Forest, Germany (© Klaus Echle/Minden Pictures)

Necropolis near Dargavs, North Ossetia, Russia (© Yakov Oskanov/Shutterstock)

An unkindness of ravens in Juneau, Alaska, USA (© Brian Browitt Photo/Adobe Stock)

Misty pine forest in the Central Highlands of Vietnam (© Thanh Thuy/Moment/Getty Images)

Grotesques at York Minster, York (© John Potter/Alamy)