Ait Hamou ou Said Kasbah, Draa Valley, Morocco, North Africa

Kasbah near El Kelaa M'Gouna, Dades Valley, High Atlas mountains, Morocco, North Africa

Multi-storey mud brick houses, Habban, Lower Hadramaut, Yemen, Middle East

Gum trees in a billabong at Rawnsley and the south west escarpment of Wilpena Pound, a huge natural basin, Flinders Ranges National Park, South Australia, Australia

Backpacker walking across dried up lake towards Llaima volcano, Conguillio National Park, Chile, South America

Steaming volcanic mud pools, Rincon de la Vieja National Park at foot of Rincon Volcano, Gaunacaste, Costa Rica

Ait Arbi Kasbah, Dades Valley, High Atlas mountains, Morocco, North Africa

Hot pools and boiling mud at Namaskard thermal area, Hverarond, near Lake Myvatn, North area, Iceland, Polar Regions

Desert-dwelling Elephant, (Loxodonta africana africana), Dry River, Hoanib, Kaokoland, Namibia

Water buffalo in mud pool in rice field, Sagada Town, The Cordillera Mountains, Benguet Province, Luzon, Philippines, Southeast Asia, Asia

Schloss Aggstein with River Danube, Wachau, Austria

Blisters measuring about 10 cm across in boiling mud pool, Mud volcano, Yellowstone National Park, UNESCO World Heritage Site, Wyoming, United States of America (U.S.A.), North America

Red sandstone rocks, with Muddy Mountains in the background, in the Valley of Fire State Park, Nevada, United States of America, North America

A female member of a mountain rescue team on the radio, Lake District, Cumbria, England, United Kingdom, Europe

Bubbling mud pools and geothermal ground on Krafla mountain near Myvatn, Iceland, Polar Regions

A mud Hut in Volcanoes National park. Typical dwelling for the people who live in the mountains of Rwanda. Volcanoes National Park, Virunga mountains, Rwanda, East Africa

A female member of a mountain rescue team on the radio, Lake District, Cumbria, England, United Kingdom, Europe

Glacier lake on Ngozumpa glacier with Cho Oyu (8201), Khumbu Himal, Sagarmatha National Park, Nepal

Camper on a destructed road from the rain in national park Lauca on the way to national park Reserva Nacional Las Vicunas, Chile, South America

Drone shot, view of the Aenok marshland with river Kamajakka, birch forests, autumn, intense colours, Vallespiken mountain on the left, Sarek mountains in the background, Kvikkjokk, Jokkmokk, Norrbottens laen, Lapland, Northern Sweden, Sweden, Europe

Drone shot, view of the Aenok marshland with lake, birch forests, deep colouring, autumn, intense colouring, Sarek mountains in the background, Kvikkjokk, Jokkmokk, Norrbottens laen, Lapland, Northern Sweden, Sweden, Europe

Burchells Zebra (Equus burchellii) standing in marshland, swamp drinking water. Background is landscape scenery with termite mount and trees. Okavango Delta, Botswana, Africa

Glacier lake on Ngozumpa glacier with Arakamtse (6423) and Cholatse (6335), Khumbu Himal, Sagarmatha National Park, Nepal

Skier walking through snow in mountains

Muddy racer at a mountain bicycle race held in Durango, Colorado in 1992 during the first years of the sport. Durango was and has been a Mecca for Mountain bikers throughout the nation.