acropolis
asylum
bastion
beachhead
bird sanctuary
blockhouse
bridgehead
bulwark
bunker
castle
citadel
donjon
fasthold
fastness
forest preserve
fort
fortification
fortress
game preserve
game sanctuary
garrison
garrison house
harbor
harbor of refuge
harborage
haven
hold
keep
martello
martello tower
mote
motte
peel
peel tower
pillbox
port
post
preserve
rath
redoubt
refuge
safe haven
safehold
sanctuary
snug harbor
strong point
tower
tower of strength
defence
defense
defensive structure
dungeon
arsenal
chieftain
defender
defenses
dwelling
encampment
frontier
mansion
monastery
outpost
province
rampart
seaport
settlement
territory