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.

David Tipling / Visitors viewing Grey Seal colony at Winterton Dunes, Norfolk, December 2010

Christophe Courteau / Mountain gorilla silverback, male called Munyinya, (Gorilla beringei) with tourist taking photo, part of Hirwa Group, Volcanoes National Park, Rwanda

Rob Jordan / 2020VISION / Atlantic salmon (Salmo salar) leaping up the cauld at Philphaugh Salmon Viewing Centre near Selkirk, where members of the public can view the spectacle, Selkirkshire, Scotland, UK, October 2011

Tim Fitzharris / Tourists viewing Grand Prismatic Pool, Midway Geyser Basin, Yellowstone National Park, Wyoming

SCOTLAND: The Big Picture / White Tailed Eagle (Haliaeetus albicilla) nest viewing hide run by the community trust in partnership with the RSPB. With plastic eagle foot showing bird rings, Mull, Scotland, UK, June.

SCOTLAND: The Big Picture / White tailed eagle (Haliaeetus albicilla) nest viewing hide run by the community trust in partnership with the RSPB, Scotland, UK, June/

Sven Zacek / Hiking trail with boardwalk and viewing platform over frozen bog pools, aerial view. Endla Nature Reserve, Jogevamaa, Central Estonia. December 2016.

Sven Zacek / Suur Munamagi hill and viewing tower at sunrise. The highest point in the Baltic States at 318m above sea level. Vorumaa, Southern Estonia. February 2018.

Karine Aigner / Tourists viewing Mexican free-tailed bats (Tadarida brasiliensis) leaving maternity colony at night to feed. This viewing is organized by Bat Conservation International. Bracken Cave, San Antonio, Tex...

Karine Aigner / Tourists viewing Mexican free-tailed bats (Tadarida brasiliensis) leaving maternity colony at night to feed. This viewing is organized by Bat Conservation International. Bracken Cave, San Antonio, Tex...

Karine Aigner / Tourists viewing Mexican free-tailed bats (Tadarida brasiliensis) leaving maternity colony at night to feed. This viewing is organized by Bat Conservation International. Bracken Cave, San Antonio, Tex...

Karine Aigner / Tourists viewing Mexican free-tailed bats (Tadarida brasiliensis) leaving maternity colony at night to feed. This viewing is organized by Bat Conservation International. Bracken Cave, San Antonio, Tex...

Karine Aigner / Tourists viewing Mexican free-tailed bats (Tadarida brasiliensis) leaving maternity colony at night to feed. This viewing is organized by Bat Conservation International. Bracken Cave, San Antonio, Tex...

Karine Aigner / Black and white image of tourists viewing Mexican free-tailed bats (Tadarida brasiliensis) leaving maternity colony at night to feed. This viewing is organized by Bat Conservation International. Brack...

Karine Aigner / Black and white image of tourist viewing Mexican free-tailed bats (Tadarida brasiliensis) leaving maternity colony at night to feed. This viewing is organized by Bat Conservation International. Bracke...

Karine Aigner / Black and white image of tourists viewing Mexican free-tailed bats (Tadarida brasiliensis) leaving maternity colony at night to feed. This viewing is organized by Bat Conservation International. Brack...

Ashley Cooper / The Perlan building in Reykjavik, Icleand. The structure was designed around 5 huge water tanks that hold geothermally heated water. This hot water is used to provide heating for nearby buildings. Se...

Ingo Arndt / Iguazu Waterfalls and tourists on viewing platform, Iguazu Falls, Iguazu National Park, Brazil, January 2014.

Ingo Arndt / Landscape of Iguazu Falls in mist, with tourists on viewing platform, Iguazu Falls, Iguazu National Park, Brazil, January 2014.

Ingo Arndt / Landscape of Iguazu Falls in mist, with tourists on viewing platform, Iguazu Falls, Iguazu National Park, Brazil, January 2014.

Enrique Lopez-Tapia / Observation tower in the rainforest, Rio Platano Biosphere Reserve and UNESCO World Heritage Site, La Mosquitia, Honduras.

Gabriel Rojo / Viewing platform and Perito Moreno Glacier, Los Glaciares National Park, Santa Cruz, Patagonia, Argentina. February 2010.

Gabriel Rojo / Look out point and sign with rules for visiting and viewing Perito Moreno Glacier Parque Nacional , Los Glaciares, Santa Cruz, Patagonia Argentina

Gabriel Rojo / Two people at viewing point overlooking Perito Moreno Glacier, Los Glaciares National Park, Santa Cruz, Patagonia, Argentina. February 2010.

Pal Hermansen / Public viewing of finished installation 'Syljusal' by artist Jan Erik Sorenstuen. Valer, Ostfold County, Norway. September 2014.

Will Watson / Geologists viewing Quartz Conglomerate exposure, Upper Devonian, Huntsham Hill, Wye Gorge, Herefordshire, UK, April 2013.

Kirkendall-Spring / Lookout point on top of Mount Pilchuck, Mount Pilchuck State Park, Cascade Mountains, Washington, USA, July 2014. Model released.

Kirkendall-Spring / Lookout point on top of Mount Pilchuck, Mount Pilchuck State Park, Cascade Mountains, Washington, USA, July 2014. Model released.

Steve O. Taylor (GHF) / Guides viewing giraffe rock engraving , northern Niger, 2005.

Hougaard Malan / Tourists on a viewing deck overlooking glacier. Perito Moreno Glacier, Patagonia, Argentina. April 2013. Non-ex.

Chris Mattison / Viewing hide next to pond in Rainham Marshes, RSPB Reserve, London, UK. May 2014.

Ingo Arndt / Tourists on viewing platform, Iguacu Falls, Iguacu National Park, Brazil

Sergey Gorshkov / Photographer Sergey Gorshkov viewing Red fox (Vulpes vulpes) through window, Kamchatka, Far East Russia.

Ingo Arndt / Tourists on viewing platform, Iguacu Falls, Iguacu National Park, Brazil

Ernie Janes / Bird watcher at RSPB Minsmere, Suffolk, England, UK, August 2013.

Wild Wonders of Europe / Lundgren / Tourists viewing Russian sturgeon (Acipenser gueldenstaedtii) in an aquarium, Danube Delta Eco Tourism Museum Center, Tulcea, Romania, June 2013. Critically endangered.

Loic Poidevin / Female Grizzly bear (Ursus arctos horribilis) standing up, Khutzeymateen Grizzly Bear Sanctuary, British Columbia, Canada, June.

Georgette Douwma / Greenband / Red Sea parrotfish (Scarus collana) browsing on filamentous algae growing on sand . Egypt, Red Sea.

Christophe Courteau / Pack of African wild dogs (Lycaon pictus), Mala Mala Game Reserve, South Africa, June.

Michele Westmorland / Tourists viewing Spotted eagle rays (Aetobatus narinar) from a inflatable. Galapagos Islands, January 2012. Model released.

Edwin Giesbers / European lynx (Lynx lynx) looking up a tree, captive, Norway, February.

Michele Westmorland / Tourists viewing Galapagos giant tortoises (Chelonoidis nigra) taking mud bath, Galapagos Islands, January 2012. Model released.

Michele Westmorland / Divers viewing a large school of scalloped hammerhead sharks(Sphyrna lewini) Galapagos Islands.

David Pattyn / Red fox (Vulpes vulpes) sitting in a meadow, looking up, The Netherlands, August.

Roger Powell / Pair of Little owls (Athene noctua) perched on a wall, looking up, Castro Verde, Alentejo, Portugal, April.

Roger Powell / Pair of Little owls (Athene noctua) perched on a wall, with the male looking up, Castro Verde, Alentejo, Portugal, April.

Roger Powell / Little owl (Athene noctua) perched on a wall, yawning, Castro Verde, Alentejo, Portugal, April.

Roger Powell / Litte owl (Athene noctua) perched on a rock, Castro Verde, Alentejo, Portugal, April.

Roger Powell / Little owl (Athene noctua) perched on a fence post, looking up, Castro Verde, Alentejo, Portugal, April.

Denis-Huot / Leopard (Panthera pardus) looking at vultures near its prey, Masai-Mara Game Reserve, Kenya

Denis-Huot / Leopard (Panthera pardus) looking at vultures near its prey, Masai-Mara Game Reserve, Kenya

Roland Seitre / Guide watching Uvea Parakeet (Eunymphicus uvaeensis) feeding on fruit, Gossanah, Ouvea, Loyalty Islands Province, New Caledonia, August 2012

Alex Mustard / People watch Sockeye salmon (Oncorhynchus nerka) migration from a viewing platform over Adams River. Part of the eco-tourism associated with the salmon run. Adams River, British Columbia, Canada, Octo...

Merryn Thomas / Viewing platform on the summit of the Schilthorn (2,970m), Bernese Oberland, Switzerland, June 2012.

Franco Banfi / Piraputanga (Brycon hilarii) in the main spring with people standing on nearby viewing platform, Aqua¡rio Natural that goes in the Rio Bai­a Bonita, Bonito, Mato Grosso do Sul, Brazil

Franco Banfi / Piraputanga (Brycon hilarii) in the main spring with people standing on nearby viewing platform, Aqua¡rio Natural that goes in the Rio Bai­a Bonita, Bonito, Mato Grosso do Sul, Brazil

Flip Nicklin / Tourists viewing Dawes Glacier from zodiac, Endicott Arm, southeast Alaska

Igor Shpilenok / Photographers viewing Kamchatka Brown Bear (Ursus arctos beringianus) standing in water fishing. South Kamchatka Sanctuary, Russian Far East, July.

Franco Banfi / Tourist on viewing platform in Punta Cantor, Peninsula Valdes, Chubut, Patagonia, Argentina, Atlantic Ocean, October

Mark MacEwen / Forest elephants (Loxodonta cyclotis) in Dzanga Bai Clearing, with wooden viewing platform, Central African Republic, Africa.

Andrew Walmsley / A tourist viewing through hide window over coastal landscape. Kaikoura, New Zealand, October.

Ingo Arndt / Tourists viewing Grand Prismatic Pool, Midway Geyser Basin, Yellowstone National Park, Wyoming

Mark Carwardine / Lowering diving cage into the sea for viewing Great white shark, Guadalupe Island, Mexico (North Pacific)

Mark Carwardine / Lowering diving cage into the sea for viewing Great white shark, Guadalupe Island, Mexico (North Pacific)

Enrique Lopez-Tapia / Wildlife viewing platform, with chital deer (Axis axis) in the distance, Sundarbans National Park, the largest mangrove swamp in the world. Bangladesh. UNESCO World Heritage Site. June 2012.

Roy Mangersnes / Tourists looking at wildlife from a dedicated viewing boat on the Chobe River, Botswana, November

David Woodfall / Farmed Bison (Bison Bison) males sparring in the snow, reared for their meat and tourist viewing, Corwen, N Wales, herd originating in Eire.

David Woodfall / Farmed Bison (Bison Bison) standing next to a river in the snow, reared for their meat and tourist viewing, Corwen, N Wales, herd originating in Eire.

David Woodfall / Farmed Bison (Bison Bison) group standing next to a river in the snow, reared for their meat and tourist viewing, Corwen, N Wales, herd originating in Eire.

David Woodfall / Farmed Bison (Bison Bison) standiing around a feeding trough in the snow, reared for their meat and tourist viewing, Corwen, N Wales, herd originating in Eire.

David Woodfall / Farmed Bison (Bison Bison) head portrait in the snow, reared for their meat and tourist viewing, Corwen, N Wales, herd originating in Eire.

David Woodfall / Farmed Bison (Bison Bison) feeding on hay, reared for their meat and tourist viewing, Corwen, N Wales, herd originating in Eire.

David Woodfall / Farmed Bison (Bison Bison) head portrait in the snow, reared for their meat and tourist viewing, Corwen, N Wales, herd originating in Eire.

David Woodfall / Farmed Bison (Bison Bison) head portrait,reared for their meat and tourist viewing, Corwen, N Wales, herd originating in Eire.

David Woodfall / Farmed Bison (Bison Bison) in the snow, reared for their meat and tourist viewing, Corwen, N Wales, herd originating in Eire.

David Woodfall / Farmed Bison (Bison Bison) head portrait in the snow, reared for their meat and tourist viewing, Corwen, N Wales, herd originating in Eire.

Terry Whittaker / 2020VISION / Birdwatchers looking at birds from a viewing hide on an organised birdwatching event led by RSPB PR Officer Howard Vaughan, Rainham Marshes RSPB Reserve, RSPB Greater Thames Futurescapes Project, Rain...

Terry Whittaker / 2020VISION / Birdwatchers looking at birds from a viewing hide on an organised birdwatching event led by RSPB PR Officer Howard Vaughan, Rainham Marshes RSPB Reserve, RSPB Greater Thames Futurescapes Project, Rain...

Terry Whittaker / 2020VISION / Birdwatcher entering a viewing hide on an organised birdwatching event led by RSPB PR Officer Howard Vaughan, Rainham Marshes RSPB Reserve, RSPB Greater Thames Futurescapes Project, Rainham, Essex, UK...

Terry Whittaker / 2020VISION / Birdwatchers entering a viewing hide on an organised birdwatching event led by RSPB PR Officer Howard Vaughan, Rainham Marshes RSPB Reserve, RSPB Greater Thames Futurescapes Project, Rainham, Essex, U...

Michael W. Richards / Bengal tiger (Panthera tigris tigris) watched by tourists on Indian elephant (Elephas maximus) as part of 'tiger show', Pench National Park, Madhya Pradesh, Indian 2006

Paul Harris / 2020VISION / Farmer, Raff Ponsillo, viewing Domestic cattle from back of jeep, herd of conservation grazing cattle on Tealham Moor, Somerset Levels, UK, June 2011

Paul Harris / 2020VISION / Somerset Wildlife Trust officer, David Leach, and Farmer, Raff Ponsillo, viewing domestic cattle and discussing conservation grazing programme on Tealham Moor, Somerset Levels, UK, June 2011

Paul Harris / 2020VISION / Somerset Wildlife Trust officer, David Leach, and Farmer, Raff Ponsillo, viewing domestic cattle and discussing conservation grazing programme on Tealham Moor, Somerset Levels, UK, June 2011

Paul Harris / 2020VISION / Somerset Wildlife Trust officer, David Leach, and Farmer, Raff Ponsillo, viewing domestic cattle, herd of conservation grazing cattle on Tealham Moor, Somerset Levels, UK, June 2011

Paul Harris / 2020VISION / Somerset Wildlife Trust officer, David Leach, and Farmer, Raff Ponsillo, viewing domestic cattle, herd of conservation grazing cattle on Tealham Moor, Somerset Levels, UK, June 2011

Roberto Rinaldi / Diver viewing Yellow fan coral / Seafan (Paramuricea clavata) amongst mass of invasive algae (Caulerpa taxifolia), Strait of Messina, Southern Italy

Roberto Rinaldi / Diver viewing mass of invasive algae (Caulerpa taxifolia), Strait of Messina, Southern Italy

Andrew Parkinson / 2020VISION / Marsh harrier (Circus aeruginosus) adult female in flight over reedbed in front of viewing hide, Norfolk, UK, April

Hiroya Minakuchi / Lion's Mane (Cyanea capillata) jelly from overhead viewing the bell, Prince William Sound, Alaska

Terry Whittaker / 2020VISION / Young woman cyclist standing on stone wall viewing Rutland Water, Rutland, UK, April 2011, Model released

Terry Whittaker / 2020VISION / Young woman cyclist standing on stone wall viewing Rutland Water, Rutland, UK, April 2011, Model released.

Terry Whittaker / 2020VISION / Young man viewing Rutland Water with binoculars from bird hide, Rutland, UK, April 2011

Shattil & Rozinski / Tourists on boardwalk viewing platform watching salmon spawning along a stream and waterfall in Ketchikan, Alaska, USA. September 2010. A fish ladder to the side of the stream creates an easier route...