Colin Monteath/ Hedgehog House / Purakaunui Falls, Catlins, New Zealand

Jeff Foott / Indian Rhubarb (Darmera peltata) growing on rock in river, Cascade Creek, Yosemite National Park, California

Jeff Foott / Spring run-off, Cascade Creek, Yosemite National Park, California

Guy Edwardes / View of hikers from behind the Pericnik Waterfall, Slovenia, October 2018.

Staffan Widstrand / Wild Wonders of China / Tree frog (Amolops afghanus) female sitting on moss Tongbiguan Nature Reserve, Dehong prefecture, Yunnan province, China, May.

Yva Momatiuk & John Eastcott / Tourist next to cascades, Dynjandi Waterfall, Westfjords, Iceland

Greg Basco/ BIA / Nauyaca Waterfalls, Dominical, Costa Rica

Tony Wu / Humpback whale (Megaptera novaeangliae) executing a dramatic tail slap, throwing up a cascade of water with its powerful fluke, Vava'u, Tonga, South Pacific

Orsolya Haarberg / View of a rainbow in the spray of Bjornefossen Waterfall, Saltfjellet-Svartisen National Park, Norway, August 2015.

Jeff Vanuga / Night stars over Yosemite Falls, Yosemite National Park, California, USA, May 2014.

Juan Carlos Munoz / Water cascading down Toberia falls, Andoin, Sierra Entzia Natural Park, Alava, Basque Country, Spain, April.

Bruno D'Amicis / Tisisat Falls / Blue Nile Falls along the Blue Nile, south of Bahir Dar, Lake Tana Biosphere Reserve, Ethiopia. December 2013.

Bruno D'Amicis / Tisisat Falls / Blue Nile Falls along the Blue Nile, south of Bahir Dar, Lake Tana Biosphere Reserve, Ethiopia. December 2013.

Juan Carlos Munoz / Aerial view of waterfall on the coastline of Corcovado National Park, Osa Peninsula, Puntarenas Province, Costa Rica. December 2014.

Peter Cairns / Selfoss waterfall in autumn with snow, north Iceland, September 2013.

Juergen Freund / Wangi Falls at night illuminated by moonlight, Litchfield National Park, Northern Territory, Australia. December 2012.

Erlend Haarberg / Meltwater from Engenbreen glacier, Meloy, Nordland, Norway, August.

Alex Hyde / Takob-Akob Falls plunging 38 metres through the rainforest. Southern plateau edge, Maliau Basin, Sabah, Borneo, May 2011.

Floris van Breugel / Salto Grande waterfall with Paine Grande beyond, Torres del Paine National Park, Chile, June 2014.

Hougaard Malan / Berlin falls on a summer afternoon. Panorama route, Mpumalanga, South Africa. March 2013.

Hougaard Malan / Tugela falls surrounded by clouds on a misty morning. Royal Natal National Park, Drakensberg, South Africa. November 2010.

Hougaard Malan / Tugela falls surrounded by clouds on a misty morning. Royal Natal National Park, Drakensberg, South Africa. November 2010.

Hougaard Malan / Waterfall over deep, narrow gorge. Magwa Falls, Pondoland, Eastern Cape, South Africa, June 2012.

Hougaard Malan / Waterfall over deep, narrow gorge. Magwa Falls, Pondoland, Eastern Cape, South Africa. June 2012.

Hougaard Malan / Rainbow over the Augrabies waterfall in flood. Augrabies National park, Northern Cape, South Africa. January 2011.

Hougaard Malan / Rainbow in the spray over Victoria Falls. Zimbabwe, Africa. November 2012.

Hougaard Malan / Waterfall and autumn foliage with view to Mount Fitz Roy. El Chalten, Patagonia, Argentina. April 2013.

Floris van Breugel / A view of Pony Tail falls with Devil's Club (Oplopanax horridus) leaves in the foreground in the Columbia River Gorge, Oregon, USA. July 2011.

Robert Thompson / European common frog (Rana temporaria) on rock by waterfall, near Lac des Gloriettes dam, Pyrenees National Park, France, June.

Graham Eaton / Salmon / Trout fish (Salmo sp) jumping a waterfall on the Afon Lledr, Betws Y Coed, Wales, October

Bert Willaert / View from the top of the Ozarde waterfalls near Koyna Lake during the monsoon. Western Ghats, India, August 2010.

Kirkendall-Spring / Lower Yellowstone Falls on the Yellowstone River viewed from Artist Point, Yellowstone National Park, Wyoming, USA, June 2013.

Kirkendall-Spring / Lower Yellowstone Falls with rainbow, on the Yellowstone River viewed from Lookout Point Trail, Yellowstone National Park, Wyoming, USA, June 2013.

Kirkendall-Spring / Close up on mountain biker's foot pedalling, in Cascade foothills, Washington, USA. April 2013. Model released.

Floris van Breugel / A complex network of delicate rivulets meander through a maze of mosses, in Gifford Pinchot National Forest. Washington. May

Merryn Thomas / View of Lauterbrunnen village and waterfall, Bernese Oberland, Switzerland, June 2012.

Andy Rouse,Andy Rouse / Waterfall from ice cliffs and polar ice cap. Austfonna Polar Ice Cap, Svalbard, Arctic. August 2011. Highly commended in the GDT competition 2013

Theo Bosboom,Theo Bosboom / Icy waterfall, Getzbach, Belgian Ardennes, February 2008

Nick Garbutt,Nick Garbutt / Tourist watching masses of butterflies drinking from temporary pools. Various species including Large Orange Sulphur (Phoebis agarithe), Cloudless Sulphur (Phoebis sennae), White-angled Sulphur (Anteo...

Ben Hall / Northern fulmar (Fulmarus glacialis) in flight against a waterfall, Iceland, January

Inaki Relanzon / Long exposure of Godafoss waterfall, Iceland.

Jack Dykinga / Cibecue Creek waterfall pouring through canyon narrows, White Mountain Apache Reservation, Arizona, USA

Konstantin Mikhailov / Lake Ann surrounded by Douglas firs (Pseudotsuga menziesii) Silver firs (Abies alba) and other conifers in the area of Rainy Pass of North Cascades National Park, North Cascades National Park, Cascade...

Robert Thompson / A cascade of waterfalls falling over a cliff in woodlands. Plitvice National Park, Croatia, May 2010.

Fabio Liverani / Freshwater Crab (Potamon fluviatile) brandishing claws in defensive posture. Foreste Casentinesi National Park, Italy, July.

Jouan & Rius / Stream running through rainforest, Bako NP, Borneo, Sarawak, Malaysia

Alex Hyde / The Fairy Pools, on the Allt Coir' a' Mhadaidh river running down from the Cullin Hills, Glen Brittle, Isle of Skye, Inner Hebrides, Scotland, UK, February 2010.

Alex Hyde / The Fairy Pools, on the Allt Coir' a' Mhadaidh river running down from the Cullin Hills, Glen Brittle, Isle of Skye, Inner Hebrides, Scotland, UK, February 2010.

Luciano Candisani / Waterfall, Chapada dos Veadeiros National Park, Goias State, Brazil

Colin Monteath / Waterfall below Mount Fitzroy, Los Glaciares National Park, Patagonia, Argentina

Colin Monteath / Waterfall at dawn below Mount Fitzroy, Los Glaciares National Park, Patagonia, Argentina

Chien Lee / Stream flowing through pristine lowland rainforest in Gunung Mulu National Park, Malaysia

Jouan & Rius / Cascade flowing in Hancock gorge, Karijini National Park, Pilbara, Western Australia. August 2009

Chien Lee / Small waterfall in rainforest interior, Lambir Hills National Park, Borneo, Malaysia

Colin Monteath / Campers read in tents lit by flashlight, Cascade Saddle, Mount Aspiring National Park, New Zealand

Colin Monteath / Dart Glacier above Cascade Saddle, Mount Aspiring National Park, New Zealand

Jack Dykinga / Havasu Falls cascade behind Fremont cottonwood trees (Populus fremontii) glowing in reflected canyon light, Havasupai Reservation, Arizona, USA

Wild Wonders of Europe / Radisics / Fast flowing water, Bjelovac Cascade, River Tara, Durmitor NP, Montenegro, October 2008

Wild Wonders of Europe / Radisics / Bjelovac Cascade in moonlight, River Tara, Durmitor NP, Montenegro, October 2008

Wild Wonders of Europe / Radisics / Water flowing down the Bjelovac Cascade, River Tara, Durmitor NP, Montenegro, October 2008

Wild Wonders of Europe / Radisics / Buk Sokolovina (cascade) in Beech forest, Tara Canyon, Durmitor NP, Montenegro, October 2008

Wild Wonders of Europe / Biancarelli / Small cascade on travertine, Galovac barrier, Upper Lakes, Plitvice Lakes NP Croatia, October 2008

Inaki Relanzon / Madagascar Malachite kingfisher (Alcedo vintisioides) amongst the spray Cascade sacree / The sacred waterfall, Montagne d'Ambre National Park, North Madagascar.

Inaki Relanzon / Madagascar Malachite kingfisher (Alcedo vintisioides) Cascade sacree / The sacred waterfall, Montagne d'Ambre National Park, North Madagascar.

Inaki Relanzon / Madagascar Malachite kingfisher (Alcedo vintisioides) Cascade sacree / The sacred waterfall, Montagne d'Ambre National Park, North Madagascar.

Luciano Candisani / Waterfall, Formoso River, Bonito, Brazil

Tim Fitzharris / Little Pigeon River cascading among rocks and colorful Maple leaves, Great Smoky Mountains National Park, Tennessee

Michael Durham / A three year old boy with a Pacific Tree Frog (Pseudacris regilla)

Michael Durham / Pacific Chorus Frog (Pseudacris regilla) jumping into pond, Oregon

Tim Fitzharris / Paradise River cascade, Mt Rainier National Park, Washington

Colin Monteath / Mt Aspiring and hiker reflected in lake at dawn, Cascade Saddle, Mt Aspiring National Park, New Zealand

Tim Laman / Rain forest stream with small cascade, Batang Toru Forest, Sumatran Orangutan Conservation Project, North Sumatran Province, Indonesia.

Robert Valentic / Cascade Tree Frog (Litoria pearsoniana) in rainforest near Peachester, Sunshine Coast hinterland, Queensland, Australia.

Tim Fitzharris / Mae Ya Waterfall cascading 260 meters, Doi Inthanon National Park, Thailand

Tim Fitzharris / Mae Ya Waterfall, Thailand

Jeff Foott / Spring run-off, Cascade Creek, Yosemite National Park, California

Jeff Foott / Spring run-off, Cascade Creek, Yosemite National Park, California

Jeff Foott / Incense Cedar (Calocedrus decurrens) trees and waterfall, Cascade Creek, Yosemite National Park, California

Jeff Foott / Cascade, Avalanche Creek, Glacier National Park, Montana

Jeff Foott / Cascade, Avalanche Creek, Glacier National Park, Montana

Jeff Foott / Spring run-off, Cascade Creek, Yosemite National Park, California

Claudio Contreras / Tamul cascade, Huasteca region, Mexico, August

Robert Thompson / Cascade des Anglais, Saint Martin du Canigou, French Pyrenees. May

Guy Edwardes / Sgwd Isaf Clun Gwyn waterfall, Brecon Beacons, Powys, Wales, August 2007.

Guy Edwardes / Sgwd Isaf Clun Gwyn waterfall, Brecon Beacons, Powys, Wales, August 2007.

Guy Edwardes / Sgwd Isaf Clun Gwyn waterfall, Brecon Beacons, Powys, Wales, UK, August 2007.

Guy Edwardes / Sgwd Isaf Clun Gwyn waterfall, Brecon Beacons, Powys, Wales, June 2006.

Magnus Lundgren / Wild Wonders of China / Green cascade frog (Odorrana chloronota) Brown tree frog (Polypedates megacephalus) Lantau Island, Hong Kong, China

Magnus Lundgren / Wild Wonders of China / Hong Kong cascade frog (Amolops hongkongensis) camouflage . Tai Mo Shan Country Park, Hong Kong, China. Endemic to Hong Kong and Guangdong in the mainland China.

Magnus Lundgren / Wild Wonders of China / Hong Kong cascade frog (Amolops hongkongensis) Tai Tam Country Park, Hong Kong Island, China.

Staffan Widstrand / Wild Wonders of China / Close up of a Tree frog (Amolops marmoratus) sitting on a green leaf at Tongbiguan Nature Reserve, Dehong prefecture, Yunnan province, China, May.

Staffan Widstrand / Wild Wonders of China / Close up of a Tree frog (Amolops marmoratus) sitting on a green leaf at Tongbiguan Nature Reserve, Dehong Prefecture, Yunnan province, China, May.

Staffan Widstrand / Wild Wonders of China / Close up of a Frog (Amolops afghanus) female sitting on moss at , Tongbiguan Nature Reserve, Dehong Prefecture, Yunnan province, China, May.

Staffan Widstrand / Wild Wonders of China / Tree frog (Amolops afghanus) female, portrait, Tongbiguan nature Reserve, Dehong prefecture, Yunnan province, China, May.

Ashley Cooper / Raise Beck above Dunmail Raise, with large snow drift, Lake District, England, UK, April.

Ashley Cooper / Stockghyll Force in full flood in summer, Ambleside, Lake District, England, UK, September 2005.