Columbia subject headings:
Castles--Germany--Hesse.
Fortification--Germany--Hesse.
Historic buildings--Germany--Hesse.
Harvard subject headings:
Castles--Germany--Hesse.
Fortification--Germany--Hesse.
Hesse (Germany)--Buildings, structures, etc.
Historic buildings--Germany--Hesse.
Military architecture--Germany--Hesse--History.
Princeton subject headings:
Castles--Germany--Hesse.
Fortification--Germany--Hesse.
Historic buildings--Germany--Hesse.