I'm not even sure which decade I read this in. 1980s or 1990s? It was in a magazine I hadn't bought, but picked up somewhere. English language. Here's what I recall about the plot.
The viewpoint character has been hired to work on the construction of the Tower of Babel. (A story mentioned in Genesis, in case you didn't remember.) I think he and his buddy are bricklayers -- using trowels and mortar to put each new line of bricks on top of the previous bit.
The Tower is not yet finished, but it is huge. I don't recall if anyone gave precise figures for how many miles high it was, how many miles wide at the base, how many men were laboring on it as a full-time job, etc., but its scale went far beyond any engineering feat ever achieved by ancient civilizations in real-life history (as far as we know). I seem to recall that after the main character and the rest of his little group of new recruits arrived at the base of the tower, it took about two months for them to make the ascent (usually riding in the back of a cart or wagon, I think) to what was currently the top level. (Presumably it had taken years to get the Tower that high, but I don't recall if anyone ever said exactly how long this construction project had been underway, either.)
Eventually the top of the tower is finally within arm's reach of the dome of the heavens (or however it's described). The general idea is that the blue sky we see above is actually the inner surface of a huge dome (or sphere, or whatever) that's been placed over, or completely surrounds, the entire Earth. (I can't remember if the Earth was presumed to be flat in this story.) So of course the person in charge of this project (a king or emperor, I suppose) gives orders to tunnel into that solid obstacle and see what happens when they reach the far side!
Near as I can recall, what happens is a flood. (But my memory is quite hazy.) I think it turns out that a vast quantity of water was on the far side of the barrier. I think the Tower of Babel is wiped out by the results. I remember that the protagonist somehow survives -- I think he suddenly ends up back in the neighborhood of his home town, wherever that was. (Nowhere near the base of the Tower, I'm sure.) If any sweeping statements were made about what all this proved about the cosmology of this universe (or the Will of God, or whatever), I can't recall them now.
Note: In the Biblical account, God was sufficiently annoyed by the futile attempt to build a Tower all the way up to Heaven that he punished humanity by causing many people to start speaking different languages from what they had been speaking before. I can't recall if anything along those lines was mentioned at the end of this story. (I suspect not, but I can't swear to it after all these years.)