Hi. I have been looking for the title on a movie that I saw when I was a kid in the mid 80's. The movie was set during the war ( I think it was during the nazi era ). I remember at the beginning that they are all walking on a path and discover some sort of tower or castle that is sealed shut. They manage to open it. They discover that the castle or tower was made from the inside out. It was made like that to keep something inside the castle but since they open the door now it's free to do whatever it wants. At the end there some kind of demon inside and 1 by 1 they get killed by that demon.
Hope anyone can help me. Thank you in advance.

Perhaps The Keep (1983)?

Wowwwwwww... you got it!! Thank you very much.

Is there more movies in this style. I saw a movie where the nazi's opened a big room inside a mine. Inside it was a very big room and a kind of devil.