Historical clue formulations

• Shooter's position in a fort — 2015-03-24
• Citadel feature — 2009-11-06
• Protective wall — 2009-01-07
• Defensive wall — 2008-02-20
• Balcony's edge — 2006-10-01
• Bridge safety feature — 2004-10-30
• Balcony barrier — 2003-10-24
• Low wall — 2001-08-24
• Breastwork — 1998-12-13
• Defensive wall — 1998-01-06
• Protective wall — 1997-12-27