Columbia subject headings:
Coast defenses--Italy--Salentina Peninsula.
Salentina Peninsula (Italy)--History.
Turrets--History.
Harvard subject headings:
Fortification--Italy--Puglia--History.
Puglia (Italy)--Coast defenses.
Towers--Italy--Puglia.
Princeton subject headings:
Fortification--Italy--Otranto Region.
Puglia (Italy)--History.
Towers--Italy--Otranto Region.