Where have I heard this before ?
Sounds something like the plot of practically all the Indiana Jones movies, not to mention The Fifth Element and, well, lots more.
I doubt this is possible.
Using only Aztec or Ancient Egyptian level technology, how could the race warn the future not to mess with the evil being's prison in a way that would last an absurdly long time (let's say for simplicity it needs to survive 100,000 years) that can be easily comprehended by anything and anyone, considering how much language changes in only a few thousand years.
The first problem is that an race with that level of technology would have no way of knowing how long a material or structure would survive. Even the concept of wear and tear, weathering and corrosion over such large time scales would be beyond their ability to estimate. It's doubtful the concept of a time scale that long would meaningful to them.
It's doubtful we could make a structure that would last that long.
To put this in perspective, the oldest known structure is about 7000 years old (less than a tenth of your goal). It's worth reading it's history under modern man to get a feel for what happens old structures.
Making this even more challenging is that over the course of such a long time scale, geography changes in quite considerable ways. The best example is Doggerland.
Until about several thousand years ago there was no North Sea and you could walk to France from the UK !
This is the kind of change that can happen in thousands of years, and the kind of changes your builders would have no comprehension of. Anything they build could be made a mockery of by geology and time.
Take a container about the size of a biscuit tin. Bring it to work and put a large sign on it saying "do not open - deadly snake inside". How long do you think it would be before someone decided they had to know if there really was a deadly snake inside and that opening it was the best way to find out ?
People are curious and telling them they can't open something to see for themselves is just asking for trouble.
Now let's apply this to your mysterious prison. Over the course of 100,000 years it is inconceivable that no matter what you say about what's inside, someone won't open it up. And that's assuming they actually understand your warnings.
And that's not new. The people in your story planning to build this would know that as well - it would be a fact in their day as much as in ours.
Let's say that an ancient race of beings locked away some sort of evil that could destroy the world if unleashed. Let's also say that unleashing it would be relatively easy to do if not warned of danger.
So whatever you do you need pictures. Rock, to anyone of that time, lasts longest and they'd use the hardest rock they could. They use redundant messages, repeats in all the languages they knew and all the painting they could.
When I say rock, I means lots of rock. Mountains of rock. Covered in more rock. With clay and earth and sand and lots more rock.
And they'd create a group that was dedicated to passing the knowledge down from generation to generation.
And, like all who tried that before them, it would get muddled and fail. The stories would become myth and legend in time. Few would believe them and those that did would be considered a bit whacko - the tin foil hat brigade.
But if someone did believe these horror stories, there's one last bit f psychology to consider :
Some idiot would actually want to unleash the horror.
So, even if they succeeded in warning people, over the course of 100,000 years some group is going to open it either due to curiosity, stupidity or because they want to see the world burn.