Ravelin

Triangular fortification

A ravelin is a triangular fortification or detached outwork, located in front of the innerworks of a fortress (the curtain walls and bastions). Originally called a demi-lune, after the lunette, the ravelin is placed outside a castle and opposite a fortification curtain wall. The ravelin is the oldest and at the same time the most important outer work of the bastion fortification system.

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