Tower of Babylon... what was it?

The truth of the answer of this will make perfect sense to anyone familiar with the concept of the cargo cults that arose on islands in the Pacific Ocean which were used as impromptu air bases during the second world war.

For those who are unfamiliar, the US troops would give some of the natives of these islands a share of their supplies as a gesture of good will whilst they were using their island.
When the war ended and the troops left, the natives began building wooden replicas of the warplanes on the abandoned air strips, and lighting large bonfires, trying to tempt these beings who entered their world from the sky, to return with more supplies.

Of course the return did not happen, but this occurrence does have a historical parallel with a lost meaning in the biblical account of the fall of the Tower of Babel. Modern uninformed historians dismiss this as a mythical attempt to explain why multiple languages are spoken on earth. This, in fact, is not the focus of the story, but the outcome.
The ancient people of the world, beginning with the Sumerian civilisation, worshipped a group of beings collectively known as the 'Anunnaki' a name which to them meant 'Those who from the heavens came'

See the parallel there? Yep.

The exact influence of what the Anunnaki did for mankind isn't the focus of this post, and as it is a long and complicated account, I won't go into it any more than necessary.
The Anunnaki call another planet home, and in the time that their presence here was regular and and unhidden, they arrived on and departed from earth in a form of highly advanced rocket, launching from the top of towers which they built for that purpose. When their presence on earth was no longer required and they began leaving, the people of the world responded to this by building their own tower, and placing a mockup of one of these rockets at it's peak, in an attempt to entice these beings that they saw as gods to return.

The Anunnaki response to this was deep concern. In their view, given this achievement that mankind had achieved by working together, it would not be long before they were able to construct a functional rocket and reach 'heaven'. Again, another world that many in the modern world are incapable of comprehending, is synonymous with 'sky', at least in one context. The biggest problem with this was that mankind was not evolved enough to safely enter the interstellar community without being a danger to others already there.

And so, the tower was destroyed, and where previously in my view all of mankind would have been bi-lingual, given that these were the collective descendants of the three sons of Noah, and we know each of those three groups had a different language, they must have retained enough of the language of Noah to communicate with each other effectively.

1 And the whole earth was of one language, and of one speech.
2 And it came to pass, as they journeyed from the east, that they found a plain in the land of Shinar; and they dwelt there.
3 And they said one to another, Go to, let us make brick, and burn them throughly. And they had brick for stone, and slime had they for morter.
4 And they said, Go to, let us build us a city and a tower, whose top may reach unto heaven; and let us make us a name, lest we be scattered abroad upon the face of the whole earth.
5 And the LORD came down to see the city and the tower, which the children of men builded.
6 And the LORD said, Behold, the people is one, and they have all one language; and this they begin to do: and now nothing will be restrained from them, which they have imagined to do.
7 Go to, let us go down, and there confound their language, that they may not understand one another's speech.
8 So the LORD scattered them abroad from thence upon the face of all the earth: and they left off to build the city.

9 Therefore is the name of it called Babel; because the LORD did there confound the language of all the earth: and from thence did the LORD scatter them abroad upon the face of all the earth.
— Genesis 11:1–9

To me this indicates that they were stripped of their common language as the tower fell, and scatterred to different parts of the earth.

It may be that parts of this are inaccurate, but a large portion I know to be fact as a result of many years of research. In the case of the parts I don't know for certain, I will admit I used logic to try to make the best guess possible to me