Illustrated glossary

Demi-lune or ravelin

An entrenched structure in front of the curtain wall of a bastioned front, entirely surrounded by ditches. A triangular ravelin generally had two faces at an acute angle, but could also have two flanks. It often protected the entrance gate to the stronghold.
Demi-lune or ravelin: An entrenched structure in front of the curtain wall of a bastioned front, entirely surrounded by ditches.