So this was previously solved for me on here before and I can’t find the post now.
This is a foreign film released in the US under a different title. I want to say German?
It’s about these kids who go looking for treasure. The VHS cover was the opening of a cave with a kid falling into it. There is a scene with quicksand. Ripping apart the spines of books to find clues/map pieces. A skeleton wearing jewels and a chastity belt. A man with his head over a bowl of hot water with a towel over his head.
I want to say it’s “The Four Adventures” or something along those lines.