Spain, Castile and Leon, Avila, City walls that were built from 1090 onwards and are among the best-preserved and most complete in Europe, viewed from the walkway along the interior perimeter of the w...

Switzerland, Piz Bernina, Seen from Morteratsch Glacier with the Labyrinth on the left in the distance.

Switzerland, Aerial view from Furkpass of the Upper Rhone Valley with clouds formed in drifts over Grihselpass in the distance.

Switzerland, Central, Western descent road from the Furkapass with the road to Grimselpass in the distance beneath snow covered peaks.

Farming, Crops, Wheat, View over field of unripe wheat in the foreground and other fields in the distance.

Australia, Western Australia, Nambung National Park, The Pinnacles Desert. Flat sandy range with limestone pillars leading in to the distance.

Iceland, Snaefellsnes Peninsula National Park, Djupalonssandur black sand beach. Rock formations with Snaefellsjokull, a 700,000-year-old glacier-capped stratovolcano in the distance.

Iceland, Snaefellsnes Peninsula National Park, Arable farm and fields. With snow capped mountains in the distance.

Iceland, Snaefellsnes Peninsula National Park, Arable farm and fields. With snow capped mountains in the distance.

Iceland, Snaefellsnes Peninsula National Park, Arable farm and fields. With snow capped mountains in the distance.

Iceland, Golden Circle, Thingvellir National Park in Autumn colours. The Mid-Atlantic Rift between the North American and Eurasian tectonic plates. Fissures in the landscape with Lake Thingvallavtn in...

Afghanistan, Bamiyan, View over town buildings with mountains in the distance.