The premise is simple: humans, ever curious, build their own "don't push" button in the shape of a giant tower, eventually hoping to reach up all the way to the heavens, supposed to be god's humble abode. Needless to say, god (who values his privacy) is pretty riled about this. For once not in a smiting mood, all he needs to do is confound their language. Hilarious confusion ensues, Project Tower is immediately abandoned, The End.
The idea of god's domicile being a tangible location "up above", together with some really muddled notions about the shape of the earth, later "logically" led to the placement of hell "down below" - although hell as a concept was added only much, much later (have no fear, in due time I hope to put hell on the map - as it were - as well). Strictly speaking (and to avoid offending Aussies), we'd now have to say that heaven is "all around us", otherwise one man's heaven would be antipodal man's hell. The whole idea only works (barely, if that) if you assume the earth to be flat, with some sort of baldachin (the firmament) for a roof (early "maps" like that really exist - where earth is square & flat, with a canopy, like a four poster...). But as we now know it isn't, and hasn't, we can safely discard yet another bible fairytale to the dustbin of history.