Directed by Jesús Franco, is an English-language co-production among various European countries including the UK, Spain,[6] and West Germany.

[8] Supercriminal Dr. Fu Manchu plots to freeze the world's oceans with a diabolical new device.

With his beautiful but evil daughter, Lin Tang, his army of dacoits, and the help of the local crime organization led by Omar Pasha (whom Dr. Fu Manchu double-crosses), Dr. Fu Manchu takes over the governor's castle in Istanbul, which has a massive opium reserve, to control the largest opium port in Anatolia, since the drug is an important ingredient for the fuel for his machine.

[7] The Castle of Fu Manchu was released on May 30, 1969 in West Germany and on September 24, 1970 in Kingston, Jamaica.

[13] In 1992, The Castle of Fu Manchu was featured in Mystery Science Theater 3000 (Season 3, Episode 23).