Here's why….while the film's production standards and set design were as flawless as ever, this Hammer Horror film had very little horror and felt more like a melodrama. I thought I was watching an episode of Downton Abbey! Finally, when the horror element arrived, it was done poorly and came across as really fake. About the only reaction it got from me was a groan.
The concept was interesting. The Gorgon, which in Greek mythology, were three sisters [the best known of which is Medusa] had snakes for hair that turned everyone to stone who gazed into their eyes. Somehow one of these ancient, mythic beings takes human form and terrorizes a European Village. It sounds like an interesting premise but the execution of it was not interesting at all. Perhaps with a stronger screenplay it could have worked. Unfortunately, there is no back story in the film regarding how all this came about and why a Gorgon chose this particular village to haunt.
Finally, while Peter Cushing was up to his usual excellent performance, Christopher Lee seemed a bit flat. It felt like his costume was wearing him and he was simply taking up space on screen.
With all the wonderful Hammer Horror films out there, I'd suggest you watch them first before tackling this one.
For more info check out the film's entry in IMDB.