One Does Not Simply

• Berlin wall, failed
• Wall of Constantinople, failed, abandoned
• Great Wall of China failed, abandoned, a whole new dynasty sprung from invadors
Antonine Wall, failed in less than 15 years
• Hadrian Wall, failed, lasted one emperor
• Athenian Wall, failed
• Wall of Jericho, failed

Walls work for small area, they cannot protect large borders and have repeatedly failed in history.