Category Nuances for fortification:

• effective,
• military,
• public,
• immovable,
• armored,
• urban,
• new,
• defensive,
• solid,
• passive,
• monumental,
• local,
• visible,
• historic,
• protective,
• valuable,
• fixed,
• important,

Simple Categories for fortification:

• structure,
• action,
• area,
• defense,
• monument,
• measure,
• artifact,
• item,
• object,
• building,
• relic,
• edifice,
• improvement,
• skill,
• installation,