tRUMP Said: "Walls Work." Reagan Said: "Mr Gorbachev, Tear Down This Wall." - Did the Great Wall of China Work? Did it Keep the Chinese OUT?

The Truth is that the Great Wall of China is in the Middle of the Country with Chinese People on BOTH SIDES! Total Failure!

Did the Berlin Wall Work? Did Hadrian's Wall Work?

What about Pink Floyd's WALL? https://www.youtube.com/watch?v=kAGkuPaatdc