Fabio Pupin / Moorish gecko, (Tarentola mauritanica), hunting on window, Italy, April . Non-ex.

Theo Bosboom / Crashing waves at large basalt wall, Arnarstapi, Snaefellsnes, Iceland. May 2013

Jack Dykinga / Border wall with razor wire at the Mexican / United States border in Arizona, where the newer taller sections of the border wall pushed by President Trump are being erected in the environmentally sens...

Jack Dykinga / Bird caught in border wall mesh at the Mexican / United States border, Organ Pipe National Monument, Arizona, USA, August.

Jack Dykinga / Mexican / United States border in Arizona, where the newer taller sections of the border wall pushed by President Trump are being erected in the environmentally sensitive Organ Pipe National Monument....

Jack Dykinga / Mexican / United States border in Arizona, where the newer taller sections of the border wall pushed by President Trump are being erected in the environmentally sensitive Organ Pipe National Monument....

Jack Dykinga / Mexican / United States border in Arizona, where the newer taller sections of the border wall pushed by President Trump are being erected in the environmentally sensitive Organ Pipe National Monument....

Jack Dykinga / Saguaro cacti (Carnegia gigantea) at sunset, during a summer rain storm. Saguaro National Park, Sonoran Desert, Arizona, USA, August. Digital composite.

Jack Dykinga / Landscape at the older Mexican / United States border wall in Arizona. Newer taller sections of the border wall pushed by President Trump are being erected in this environmentally sensitive Organ Pipe...

Yashpal Rathore / Bengal tiger (Panthera tigris tigris) dominant male (T29) walking on mud dam wall. Kanha National Park, Central India. Camera trap image.

Yashpal Rathore / Bengal tiger (Panthera tigris tigris) (T27) walking on bund / dam wall trail. Kanha National Park, Central India. Camera trap image.

TJ Rich / Four chocolate working cocker spaniels on wall. Mother and offspring. Monmouth, Monmouthshire, Wales