Jack Dykinga / The humpback chubs (Gila cypha) amid Grand Canyon wall reflections in the Colorado River near the confluence with the Little Colorado River. Arizona. Vulnerable species.

Alex Mustard / Caribbean reef squid (Sepioteuthis sepioidea) North Wall, Grand Cayman, Cayman Islands, West Indies, Caribbean Sea

Alex Mustard / A Caribbean reef squid (Sepioteuthis sepioidea) perches on the hand of a diver. North Wall, Grand Cayman, Cayman Islands, West Indies, Caribbean Sea, April 2008, no release available.

Jeff Rotman / Child snorkeling and exploring on coral reef wall. Red Sea, Egypt. Model released Model released.

Diane McAllister / The snow at Horsetail Falls' begins to melt in mid-February, enabling the falls to resume once again. The clear sky and low sun angle ignite the rock wall during sundown. Yosemite National Park, Calif...

Philip Stephen / Fishing vessel "Ocean Pioneer" nearing Fraserburgh Harbour, with waves crashing against the harbour wall. Scotland, February 2011.

Wild Wonders of Europe / Oxford / Iberian Wall Lizard (Podarcis hispanica) on rock, Sierra de Andjar Natural Park, Mediterranean woodland of Sierra Morena, north east Jan Province, Andalusia, Spain, April 2009

Philippe Clement / Western Black widow (Latrodectus hesperus) spider leaving burrow / hole in wall. Arizona, USA

Jack Dykinga / Ponderosa pine cones {Pinus ponderosa} and drift wood amid canyon wall reflections in Death Hollow, Grand Staircase-Escalante, Utah, USA

Leo & Mandy Dickinson / Great Trango wall in the Karakorum, Pakistan

Robert Thompson / Italian wall lizard (Podarcis siculus) north of San Nicandro Garganico, Gargano, Italy

Robert Thompson / Italian wall lizard (Podarcis siculus) north of San Nicandro Garganico, Gargano, Italy

Robert Thompson / Italian wall lizard (Podarcis siculus) north of San Nicandro Garganico, Gargano, Italy, April

Gavin Hellier / Wall Street and the New York Stock Exchange signs, downtown Financial District, Manhattan, New York City, USA 2009

Floris van Breugel / A lichen covered wall of eroded basalt columns along the side Potholes Coulee near Ancient Lakes region, Washington, USA, April

Claudio Contreras / Border wall established to divide USA from Mexico dividing the desert, near Sonoyta, Sonora, nortwestern Mexico.

Claudio Contreras / Border wall established to divide USA from Mexico dividing the desert, near Sonoyta, Sonora, nortwestern Mexico.

Claudio Contreras / Sand verbena (Abronia villosa) growing at the base of the border wall established to divide USA from Mexico, near Sonoyta, Sonora, northwestern Mexico.

Claudio Contreras / Border wall established to divide USA from Mexico, near Sonoyta, Sonora, northwestern Mexico.

Georgette Douwma / Red Soldierfish (Myripristis murdjan) sheltering on coral wall. Egypt, Red Sea.

LYNN M. STONE / Female Pomeranian standing by flowers on garden wall; Illinois, USA

LYNN M. STONE / Female Pomeranian standing by flowers on garden wall; Illinois, USA

Jack Dykinga / Cardinal monkey flowers line sculpted canyon wall with fallen Ponderosa pine in background, Red Rock Secret Mountain Wilderness, Arizona, USA

Jack Dykinga / Desert varnished sandstone walls with fractured and brilliantly banded canyon wall, North Wash Glen Canyon Recreation Area, Utah, USA

Paul Harris / 2020VISION / Barley crop in field, Haregill Lodge Farm, Ellingstring, North Yorkshire, England, UK, July.

Paul Harris / 2020VISION / Early Oat fields, Haregill Lodge Farm, Ellingstring, North Yorkshire, England, UK, January

Alex Mustard / Diver photographing a large formation of yellow tube sponges (Aplysina fistularis) growing on a coral reef, North Wall, Grand Cayman, Cayman Islands, British West Indies, Caribbean Sea. Model released...

Todd Mintz / Snowy owl (Bubo scandiacus) on stone wall, Canadian prairies. Saskatchewan, Canada, March

Merryn Thomas / Traveller sitting on wall, haggling for local cakes on Essaouira beach, November 2008.

Merryn Thomas / Traveller sitting on wall, haggling for local cakes on Essaouira beach, November 2008.

Rolf Nussbaumer / Black and yellow Mud Dauber (Sceliphron caementarium) females in flight bringing mud to nest inside wall. Comal County, Hill Country, Central Texas, USA, July.

Rolf Nussbaumer / Black and yellow Mud Dauber Wasp (Sceliphron caementarium) female in flight bringing mud to nest inside wall. Comal County, Hill Country, Central Texas, USA, July.

Bryan and Cherry Alexander / Inuit words in syllabics and childrens' drawings on a classroom wall at the Ataguttaaluk School in Igloolik, Nunavut, Canada, 2002.

Fabio Liverani / Sign painted on wall advertising an internet cafe. Medina quarter, Fes, Morocco, December 2010.

Matthias Breiter / Giant Green Sea Anemone (Anthopleura xanthogrammica) group and Ochre Sea Stars (Pisaster ochraceus) on rock wall on St. Lazaria Island, Alaska

Toby Roxburgh / Rock mounds laid out as coast defence along the shoreline just north of the old Severn Crossing, River Severn, England, 2010.

Jerry Monkman / Sap buckets attached to the trunks of Sugar maple trees (Acer saccharum) to collect the maple sap, stone wall, Lyme, New Hampshire, USA, March 2007

Bryan and Cherry Alexander / Woman using an outdoor toilet screened from the wind by a wall of snowblocks. Nunavut, Canada, 1999.

Jerry Monkman / Woodland trail in Odiorne State Park, Rye, New Hampshire, USA, August 2008.

LYNN M. STONE / Domestic dog, Australian Shepherd (note the different colored eyes, common in this breed) Voluntown, Connecticut, USA (SR)

Konrad Wothe / Wall Lizard (Mesalina sp) on sand, Libya

Robert Thompson / Stone wall, Bouleevin, Killenmacoog, North Burren, County Clare, Republic of Ireland, July 2007

Mike Potts / Chough (Pyrrhocorax pyrrhocorax) recently fledged younster perched on wall calling, South Stack, Anglesey, North Wales, UK

Mike Potts / Chough (Pyrrhocorax pyrrhocorax) recently fledged youngster perched on wall, South Stack, Anglesey, North Wales, UK

Ross Hoddinott / Rustyback fern (Ceterach officinarum), growing in wall, near Hartland, north Devon, UK. December

Philippe Clement / Harbour wall and lighthouse at Saint-Vaast-la-Hogue, Normandy, France, December 2008

Philippe Clement / Harbour wall and lighthouse at Saint-Vaast-la-Hogue, Normandy, France, December 2008

Philippe Clement / Waves crashing into jetty and over harbour wall during storm at Saint-Valéry-en-Caux, Normandy, France, December 2008

Philippe Clement / Waves crashing into jetty and over harbour wall during storm at Saint-Valéry-en-Caux, Normandy, France, December 2008

Juan Manuel Borrero / Wall of Meknes, Morocco, March 2009

Shattil & Rozinski / Construction of the boundary wall between the USA and Mexico, Lower Rio Grande Valley, Texas, USA ILCP RAVE January/February 2009

Shattil & Rozinski / Sign protesting against the US / Mexico border wall, Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP RAVE January/February 2009

Shattil & Rozinski / Construction of the US / Mexico border wall in Hidalgo County, Texas, along the Lower Rio Grande wildlife corridor, USA ILCP RAVE January/February 2009

Shattil & Rozinski / Construction of the border wall between USA and Mexico in a wildlife corridor, Lower Rio Grande Valley, Texas, USA ILCP RAVE January/February 2009

Shattil & Rozinski / Construction of the US / Mexico border wall along the Lower Rio Grande wildlife corridor, Hidalgo County, Texas, USA ILCP RAVE January/February 2009

Shattil & Rozinski / Wetland area acquired by the Santa Ana National Wildlife Refuge showing the disruption of the US / Mexico border wall construction. Before the wall, this valuable habitat was part of an important widl...

Shattil & Rozinski / Aerial view of the US / Mexico border wall in Hidalgo County showing how wildlife corridors are severed, reduced or eliminated by the wall, Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP R...

Shattil & Rozinski / Area of wetland acquired by the Santa Ana National Wildlife Refuge showing the disruption of the US / Mexico border wall construction. Before the wall, this valuable habitat was part of an important w...

Shattil & Rozinski / Aerial view of the US / Mexico border wall in Hidalgo County showing how wildlife corridors are severed, reduced, or eliminated, Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP RAVE January...

Shattil & Rozinski / Construction of the US / Mexico border wall along the Lower Rio Grande wildlife corridor, Hidalgo County, Texas, USA ILCP RAVE January/February 2009

Shattil & Rozinski / Aerial view of the US / Mexico border wall in Hidalgo County showing how wildlife corridors are severed, reduced, or eliminated, Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP RAVE January...

Shattil & Rozinski / US / Mexico border wall, Lower Rio Grande Valley wildlife corridor, Hidalgo County, Texas, USA ILCP RAVE January/February 2009

Shattil & Rozinski / Wetlands and wildlife habitat viewed through the US / Mexico border wall now on the no-man's-land side, near the Lower Rio Grande Valley wildlife corridor, Hildalgo County, Texas, USA ILCP RAVE Januar...

Shattil & Rozinski / Aerial view of the US / Mexico border wall in Hidalgo County, Texas showing how wildlife corridors are severed, reduced, or eliminated, Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP RAVE...

Shattil & Rozinski / Great blue heron (Ardea herodias) standing between a reclamation pond and the US / Mexico border wall, Lower Rio Grande Valley wildlife corridor, Hidalgo County, Texas, USA ILCP RAVE January/February...

Shattil & Rozinski / Photographer, Wendy Shattil, photographing through the bars of the US / Mexico border wall in Hildalgo County near the Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP RAVE January/February...

Shattil & Rozinski / Snowy egret (Egretta thula) standing next to a reclamation pond and the US / Mexico border wall near the Mexican border Lower Rio Grande Valley wildlife corridor, Hidalgo County, Texas, USA ILCP RAVE...

Shattil & Rozinski / US / Mexico Border wall construction in progress in Hidalgo County, Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP RAVE January/February 2009

Shattil & Rozinski / Juvenile Peregrine falcon (Falco peregrinus) perched on wall flapping wings, captive, Denver, Colorado, USA

Shattil & Rozinski / Aerial view of the Mexico / US border wall in Hidalgo County showing how wildlife corridors are severed, reduced, or eliminated, Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP RAVE January...

Shattil & Rozinski / Aerial view of the US / Mexico border wall in Hidalgo County showing how wildlife corridors are severed, reduced, or eliminated, Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP RAVE January...

Shattil & Rozinski / Pedestrian bridge over the Rio Grande at Progresso, the US / Mexico border wall is viewed by tourists walking from the US side, Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP RAVE January/...

Shattil & Rozinski / Aerial view of the US / Mexico border wall in Hidalgo County showing how wildlife corridors are severed, reduced, or eliminated, Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP RAVE January...

Shattil & Rozinski / Raccoon (Procyon lotor) tracks along the length of the US / Mexico border wall (no mans land between the wall and the Rio Grande) Lower Rio Grande Valley wildlife corridor, Hidalgo County, Texas, USA...

Shattil & Rozinski / Bobcat (Felis rufus) tracks along the US / Mexico border wall on the no-man's-land side of the wall (between the wall and the Rio Grande) Lower Rio Grande Valley wildlife corridor, Hidalgo County, Tex...

Shattil & Rozinski / Aerial view of the US / Mexico border wall in Hidalgo County showing how wildlife corridors are severed, reduced, or eliminated, Lower Rio Grande Valley wildlife corridor, Texas, USA ILCP RAVE January...

Shattil & Rozinski / Ocelot (Felis pardalis) researcher, Jody Mays, checks the condition of a male captured earlier that day, having been fitted with a radio collar, before release. Ocelot trapping program, Laguna Atascos...

Shattil & Rozinski / Ocelot (Felis pardalis) being released after having a radio collar put on, Laguna Atascosa National Wildlife Refuge, Texas, USA. The largest known population of wild ocelots in the USA lives on this r...

Yva Momatiuk & John Eastcott / Peak above Fluted Wall formation shaped by erosion, Capitol Reef National Park, Utah

Yva Momatiuk & John Eastcott / Fluted Wall formation of multi-hued sandstone layers shaped by erosion, Capitol Reef National Park, Utah

Merryn Thomas / Seagull on wall of Essaouira old fort, Morocco, November 2008.

Merryn Thomas / Berber leaning over sea wall in Essaouira, Morocco, November 2008.

Merryn Thomas / Men and children sorting fish on wall of fishing port, with the medina in the background. Essaouira, Morocco, November 2008.

Fred Bavendam / Slate Pencil Urchin (Heterocentrotus mammillatus) pair attached to rock wall, Kona, Hawaii

Jerry Monkman / Wooden lobster buoys hang on a wall in Stonington, Maine, USA

Jerry Monkman / Wooden lobster buoys hang on a wall in Stonington, Maine, USA

GEORGETTE DOUWMA / Dog with one blue and one brown eye (wall eyed). USA.

Gary K. Smith / Cley Nature Reserve, showing freshwater marsh, reedbeds, birdwatching hides, sea wall and sea in distance, North Norfolk, UK

Inaki Relanzon / Muslim woman walks past wall, Medina del Zoco, Marrakech, Morocco

Rob Cousins / Public Footpath sign on wall with way marker signs on fence, North Cornwall, UK

Carol Walker / Boy and Gypsy Cobb stallion with wall eyes, Berthoud, Colorado, USA, model released

Norbert Wu / Strawberry Anemones (Corynactis californica), pink hydrocorals, and colorful invertebrates on rock wall in kelp forest, Point Lobos State Reserve, California

Shattil & Rozinski / Rock mimulus {Mimulus sp} growing on canyon wall, Death Valley National Monument, California, USA

Shattil & Rozinski / Rock mimulus {Mimulus sp} growing on canyon wall, Death Valley National Monument, California, USA

Shattil & Rozinski / Shadow of pillars against a stone wall, Philae Temple, Aswan, Egypt, 2007