What are some of the greatest fortresses ever built (they have been successful in repelling invaders and/or are impressive in terms of their size and ingenuity)? - Quora

At what point in history were castles the best built and strongest? - Quora

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

What are some of the greatest fortresses ever built (they have been successful in repelling invaders and/or are impressive in terms of their size and ingenuity)? - Quora

Why did the French build forts? - Quora

What are some of the greatest fortresses ever built (they have been successful in repelling invaders and/or are impressive in terms of their size and ingenuity)? - Quora

What are some of the greatest fortresses ever built (they have been successful in repelling invaders and/or are impressive in terms of their size and ingenuity)? - Quora

What are/have been the most impregnable fortresses in history? - Quora

The World's 30 Most Impressive Fortresses

What are/have been the most impregnable fortresses in history? - Quora

What is the difference between medieval and ancient fortresses? - Quora

What are some of the greatest fortresses ever built (they have been successful in repelling invaders and/or are impressive in terms of their size and ingenuity)? - Quora