The sea otter (Enhydra lutris) is a marine mammal native to the coasts of the northern and eastern North Pacific Ocean. Adult sea otters typically weigh between 14 and 45 kg (31 and 99 lb), making them the heaviest members of the weasel family, but among the smallest marine mammals. Unlike most marine mammals, the sea otter's primary form of insulation is an exceptionally thick coat of fur, the densest in the animal kingdom. Although it can walk on land, the sea otter lives mostly in the ocean.

The worlds largest cruise ship, the 361 metres long, Harmony of the Seas, arrives in port for her mayden voyage, in Southampton, Britain May 17, 2016. (Photo by Peter Nicholls/Reuters)

The Mexico – United States barrier – also known in the United States as the border fence, rotted fence or border wall – is actually several separation barriers designed to prevent illegal movement across the Mexico – United States border.

“The Berlin Wall (German: Berliner Mauer) was a barrier constructed by the German Democratic Republic (GDR, East Germany) starting on 13 August 1961, that completely cut off West Berlin from surrounding East Germany and from East Berlin. The barrier included guard towers placed along large concrete walls, which circumscribed a wide area (later known as the “death strip”) that contained anti-vehicle trenches, “fakir beds” and other defenses. The Soviet-dominated Eastern Bloc officially claimed that the wall was erected to protect its population from fascist elements conspiring to prevent the “will of the people” in building a socialist state in East Germany. However, in practice, the Wall served to prevent the massive emigration and defection that marked Germany and the communist Eastern Bloc during the post-World War II period”. – Wikipedia

Photo: West Berlin policemen and East German Volkspolizei face each other across the border in Berlin, circa 1955. (Photo by Three Lions/Hulton Archive/Getty Images)

Air conditioners, more than 500 in total, hang on the wall of an office building on August 15, 2011 in Fuzhou, Fujiang Province of China. This 25-story office building was built with no central air conditioner system, each office has it own individual unit installed on the exterior creating this wall of air conditioners. (Photo by ChinaFotoPress/Getty Images)

“The Eton wall game is a game similar to football and Rugby Union, that originated from and is still played at Eton College. It is played on a strip of ground 5 metres wide and 110 metres long next to a slightly curved brick wall, erected in 1717”. – Wikipedia

Photo: The “Collegers” and the “Oppidans” of Eton College take part in the “Wall Game” as boys in their traditional school uniform watch from on top of the wall on November 17, 2007 in Eton, near Windsor, Berkshire, England. The first recorded “Wall Game” took place in 1766 with competition between the two houses at the boarding school remaining as fierce as ever on the annual St. Andrew's day event. The object of the game is to get the ball to either end of the wall and score a goal, which has not happened since 1909. As well as scoring a goal the players can win points with a “shy”, where the ball is held against the wall and touched by the hand and awarded one point. (Photo by Christopher Furlong/Getty Images)

Portuguese runner Adriele Silva gestures during the Great Wall Marathon at the Huangyaguan section of the Great Wall of China, in Jixian of Tianjin, China May 19, 2018. (Photo by Jason Lee/Reuters)