
thumb|Two ravelins (top left of image) in Goes, The Netherlands thumb|Ravelin in the Dutch town of Bergen op Zoom thumb|300px|Ravelin protecting the entrance of Fort McHenry, [[Baltimore, Maryland]] thumb|The Moers fortifications, designed by [[Simon Stevin, where ravelins appear as triangular shapes surrounded by water, with wall (shown in dark green) facing outwards with no wall on the inner side.]]
thumb|Two ravelins (top left of image) in Goes, The Netherlands thumb|Ravelin in the Dutch town of Bergen op Zoom thumb|300px|Ravelin protecting the entrance of Fort McHenry, [[Baltimore, Maryland]] thumb|The Moers fortifications, designed by [[Simon Stevin, where ravelins appear as triangular shapes surrounded by water, with wall (shown in dark green) facing outwards with no wall on the inner side.]]
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.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).