Polar bears in Torngat Mountains National Park, Canada (© Cavan Images/Offset by Shutterstock)

Loch Leum na Luirginn and Loch Cleat seen from the Quiraing, Isle of Skye (© Sebastian Wasek/Sime/eStock Photo)

Wild reindeer swimming across the Kobuk River in Alaska, USA (© Michio Hoshino/Minden Pictures)

Houses of Parliament on a cloudy evening in London (© chbaum/Shutterstock)

West Indian manatees in Crystal River National Wildlife Refuge, Florida, USA (© Norbert Probst/Getty Images)

Bison in Grand Teton National Park, Wyoming, USA (© Brian Evans/Getty Images)

St Michael's Church on Burrow Mump, Burrowbridge, Somerset (© DEEPOL by plainpicture/Adam Burton)

The hills of Barolo vineyards in Piedmont, Italy (© Marco Arduino/eStock Photo)

Badlands National Park, South Dakota, USA (© Dennis Frates/Alamy)

A British Tommy figure at the war memorial in Selkirk (© Rob Gray/Alamy Live News)

Cambron Covered Bridge in Green Mountain Park, Alabama, USA (© Jens Lambert/Shutterstock)

Ravens in a snowstorm near Kuhmo, Finland (© Frans Lemmens/Alamy)

Oil lamps being arranged on rangoli during Diwali (© Subir Basak/Getty Images)

Lupins on the shores of Lake Tekapo in New Zealand (© Stanislav Kachyna/Shutterstock)

The interior of the Abu Simbel Great Temple in Egypt (© George Steinmetz/Getty Images)

Andy Goldsworthy's Wood Line installation along Lovers' Lane in the Presidio of San Francisco, California, USA (© Chris LaBasco/Alamy)

Derwent Island on Derwentwater in the Lake District National Park, Cumbria (© Chris Warren/Stock Photo)

Chestnut-mandibled toucan in nest cavity, Costa Rica (© Greg Basco/Minden Pictures)

Aerial view of the Aiguille du Midi in the Mont Blanc massif, France (© Amazing Aerial Agency/Offset by Shutterstock)

Inunnguaq silhouetted against the Northern Lights in Barren Lands, Northwest Territories, Canada (© Mark Duffy/Alamy Stock Photo)

Common cranes in the Drömling wetland in Germany (© Mike Friedrichs/Getty Images)

Old Town of Bern, Switzerland (© Simon Zenger/Alamy)

Huge waves crashing on rocks along Asilomar State Beach, California, USA (© Sheila Haddad/Danita Delimont)

Eilean Donan Castle, western Highlands (© CBW/Alamy)

A Siberian chipmunk, Hokkaido, Japan (© plainpicture/Score. by Aflo/Takao Onozato/Aflo)

Kalbarri National Park, Western Australia (© AWL Images/Offset by Shutterstock)

Leafless trees in the mist at sunrise, Surrey (© plainpicture/Design Pics/Charles Bowman)

Mount Taranaki, Egmont National Park, North Island, New Zealand (© Francesco Vaninetti/plainpicture)

View of the coastline at dusk, Saint Andrews, Fife (© Graham Hutchison/500px/Getty Images)