A castle wall is a defensive structure built to protect a castle from attack. The three crossword solutions for the term 'castle wall' are BAILEY (6 letters), RAMPART (7 letters), and PARAPET (7 letters). A BAILEY is an enclosed courtyard within a castle, while a RAMPART is an embankment or wall that surrounds a castle. A PARAPET is a low wall along the edge of a roof or balcony. All three of these structures are part of a castle wall and provide protection from attackers.