Columbia subject headings:
Castello visconteo (Locarno, Switzerland)
Fortification--Switzerland--Locarno.
Leonardo, da Vinci, 1452-1519.
Military architecture--Switzerland--Locarno.
Harvard subject headings:
Fortification--Switzerland--Locarno.
Leonardo, da Vinci, 1452-1519
Locarno (Switzerland)--Buildings, structures, etc.
Locarno (Switzerland)--History.
Military architecture--Switzerland--Locarno--History--16th century.
Princeton subject headings:
Castello visconteo (Locarno, Switzerland)
Fortification--Switzerland--Locarno.
Leonardo, da Vinci, 1452-1519.
Military architecture--Switzerland--Locarno.