I saw this on late night uhf TV in the U.S. (Specifically Sacramento Ca so it was either channel 31 or 40) around 1975 to 1977. However, several months later it was also playing for a night at the movie theater (one of those 70s theaters that had a calendar with a different obscure or classic or foreign movie every night). So I think it was an actual feature film. It is in color so it couldn’t have been too old
I remember it had a strange word for a name – so maybe it was foreign or maybe. A made up term (such as phantasm).
the plot points I remember. 2 girls/young women are driving and their Volkswagen bug breaks down. They find refuge in a nearby castle where some other people are present. At night once everyone retires to their rooms – all kinds of wicked stuff happens exactly what I’m not sure – murder/torture that sort of thing but very intense and disturbing
I vividly remember that one of the girls (or maybe both) escape and as she runs away she crosses over into a red dimension. Everything is suddenly tinted red. I believe demons are chasing her in this alternate dimension
At the end the girl is restrained in a hospital trying to explain what happened. It may be a nuthouse/insane asylum
this has been driving me nuts my whole life – help. Lots of movies seem to have a similar plot with the castle part – but this red dimension thing is what I can never come across