I have a wall, actually two walls, built in my garden to keep the plants in. My feline adopted the wall. She likes to stare at walls, walls are her favourites. She seems to communicate with walls.
I remember the Berlin Wall that cut a city in half. It was not so much built to keep the people out, but to keep the people in. Eventually it crumbled, because the government that built the wall crumbled. Now we have a new wall built by a President who is still waiting to have it paid for from those that it was built to keep out.
The world is a funny place really. Hadrian built a wall in the first century separating Scotland and England (although those countries did not really exist as such at the time). The Chinese built a fortified wall across the country to keep the invaders out. Today Handrian’s Wall and the Great Wall of China are tourist attractions. The wall dividing Berlin was demolished, but if you were lucky you could rescue a piece and keep it as a souvenir. The US-Mexican Wall is still being built. One Day it will be a big tourist attraction I am sure.
There must be a moral to these various wall creations, but I have not yet found it. At least we remember Hadrian because it was his wall.