Columbia subject headings:
Gardens--Germany--Heidelberg.
Hortus Palatinus (Heidelberg, Germany)--History.
Landscape architecture--Germany--Heidelberg.
Harvard subject headings:
Gardens--Germany--Heidelberg.
Heidelberger Schloss (Heidelberg, Germany)
Hortus Palatinus (Heidelberg, Germany)--History.
Landscape architecture--Germany--Heidelberg.
Royal gardens--Germany--Heidelberg.
Princeton subject headings: