A side or less important gate into a castle. Often used for raids on besieging forces, or for escape. Traces of a postern gate have been found in the remains of Hemyock Castle's NW tower.

A small gateway cut through the curtain wall or its flanking towers. Used primarily as an outlet for counter-attacking. RCHME. This postern gate was built in the 13th century.

A less important gate or entrance into a castle.