ysor123: They say living things can pass only one way. Why do they need to pass the hardest way, through the top? Also they say that this preserved the contents and ruins, but how? If people can go in, sure those who found it would have entered them, even if they don't know they can't leave and everything remains inside, they still might destroy stuff over time.

I also don't see any wall around it, how to they prevent people just go inside?