A small, low fortification, sometimes with only one entrance, sometimes with two, occasionally roofed, placed for annoyance, purposes outside the CURTAIN between the two BASTIONS.

a work constructed in a main ditch between bastions, in front of a curtain erected to protect the curtain from the battering of enemy cannon fire.

(Fr.) Line - a series of adjacent redans, of equal or differing sizes, joined at the flanks with no connecting curtains.

A defensive outwork (trench or wall) built just outside the castle wall to defend the castle ditch and to provide a secure position before and after sorties from the castle.