The Wall is the Wall: Why Fortresses Fail

 …and there he corrected many abuses and was the first to construct a wall, eighty miles in length, which was to separate the barbarians from the Romans.

Ethnic cleansing in Karabakh: the latest failure of the European diplomacy? - by Simone Zoppellaro [editorial]

If a wall can be breached, why didn't castles in the medieval age build more walls? - Quora

The Great Wall of China Is Under Siege, Travel

VistaGen pauses 2nd study in wake of phase 3 anxiety failure

Chastelet, Vadum Jacob, ﻘﺼﺮ ﺍﻠﻋﺛﺮﻩ Qasr El'Athra (fortre…

The Wall is the Wall: Why Fortresses Fail

Fortress Foundations - Setting Wall Forms on Vimeo

Medieval Warfare: How to Capture a Castle with Siegecraft

Why did castles and fortresses have star shapes with included angles in the walls and what kind of attacker would actually be stupid enough to crowd into those corners? - Quora