Castle of Frankenstein was a black and white monster movie magazine which began it's run in the 1960's. A rival to the ever-popular Famous Monsters of Filmland, COF soon carved out a niche for itself and a reputation for being the "thinking man's monster magazine".
Unlike most other magazines of it's type in the 60's and early 70's, COF was intelligently written, political, innovative and sometimes controversial. It arguably became the template for almost all modern-day movie magazines, with it's mix of critical reviews and up-to-date news as well as coverage of the burgeoning SF Fan Scene and more obscure genre interests.
Sadly petering out in the mid 70's due to various distribution problems, Castle of Frankenstein is still extremely highly regarded to this day.
Any issue from it's initial run (it was briefly revived in the late 90's-very badly!) is worth purchasing and still makes entertaining and relevant reading.