| stronghold(noun, fortress, keep, support, structure) |
| fortress(noun, stronghold, keep, support, defense) |
| bastion(noun, support, place, structure, stronghold) |
| castle(noun, fortress, keep, defense, stronghold) |
| fort(noun, stronghold, fortress, keep, defense) |
| tower(noun, structure, building, place, keep) |
| fastness(noun, structure, defense, stronghold, reinforcement) |
| fortification(noun, fortress, keep, stronghold, support) |
| bulwark(noun, support, fortification, reinforcement, fortress) |
| redoubt(noun, fortification, stronghold, support, place) |
| refuge(noun, keep, defense, stronghold, pillar) |
| donjon(noun, hold, keep, defense, fortification) |
| garrison(noun, cover, position, guard, shield) |
| chateau(noun, hold, keep, fortification, cell) |
| armored box(expression, structure, building, construction, architecture) |
| armoured box(expression, structure, building, construction, architecture) |
| box citadel(expression, structure, building, construction, architecture) |
| alcazar(noun, hold, keep, fortification, cell) |
| hold(obsolete, noun, place, structure, safety) |
| barricade(noun, cover, position, guard, shield) |