Non architect here, can somebody explain how this castle isn’t eroding away?

Aerial view of Mont Saint-Michel, a historic island castle in Normandy, France, surrounded by calm waters and a sandy causeway, bathed in golden sunlight, with medieval buildings and a towering cathedral.

Aerial view of Mont Saint-Michel, a historic island castle in Normandy, France,...

Source • Posted on 2024/07/03 • Report as duplicate • Report

r/architecture u/rileythatcher Mont-Saint-Michel medieval castle island Normandy