Gatehouse
Port Royal
Port Royal
A fortified town for self-defence, with entrance gates and walls.
A barbacan is an archaic term for a barbican, a tower at the entrance to a castle or fortified town, or a fortress at the end of a bridge.
Fortified dwellings of the Middle Ages were castles and fortified manor houses. Not all dwellings were castles, however.
acropolis
Madeira
fortress
A mine entrance is technically an 'adit'
Well his 3rd entrance is called here and now or never.
Their entrance theme is "Break It Down"