Columbia subject headings:
Castles--Japan--History.
Fortification--Japan--History--16th century.
Fortification--Japan--History--17th century.
Fortification--Japan--History--18th century.
Fortification--Japan--History--19th century.
Harvard subject headings:
Castles--Japan--History
Fortification--Japan--History.
Japan--Antiquities.
Japan--History--1185-1600.
Princeton subject headings:
Castles--Japan--History.
Fortification--Japan--History.
Japan--Antiquities.
Japan--History--1185-1600.