See how medieval castles were engineered to survive sieges — keep wall thickness, moat depth, gatehouse defenses, and battlements explained with real castle examples, a glossary, and a features-at-a-glance table.
# Medieval Castle Architecture Explained: Keep, Moat & Gatehouse Design Guide
*Last updated: July 2026*
**Medieval castle architecture is the structural design of European fortresses built between the 11th and 15th centuries: massive stone keeps, moats, drawbridges, and gatehouses that gradually gave way to great halls, private chambers, and decorative stonework as warfare and comfort standards changed.**
Every feature below served a specific defensive or residential purpose — from a keep wall thick enough to shrug off a battering ram to a spiral staircase built to favor a right-handed defender. This guide breaks down each element, with real measurements from named castles, so you can recognize the design decisions behind any fortress you visit.
What are the key features of a medieval castle?
The core architectural features of a traditional medieval castle include:
– **The Keep (Donjon):** The central, most heavily fortified tower — typically the tallest structure and the lord
