The Devils Nightmare (1971)
This is an above average example of the type of metaphysical horror film
that seemed to proliferate in Europe in the 1970's.
It's simply the story of the Devil, his minion (the succubus) and seven
tourists (each representing one of the seven deadly sins) who are forced
to spend the night in a sinister castle.
The first hour is rather plodding due to an over abundance of exposition
and very little action. Viewer patience is rewarded however during the
final half hour when Ilse (the succubus) starts doing what she does best.