For many years after Noah’s death, the people multiplied, and they all spoke the same language. At one time, they gathered in a valley and devised a plan:

“Let’s build a city and a great tower that will reach all the way to heaven!” In their pride, they wanted to build a tower to show how great and powerful they were. But God was displeased with this plan, and to put a stop to this, He confused their language.

Very soon, they were no longer able to understand one another and the work on the tower stopped. The people left the area and the great tower was left unfinished.

You can read the story of the Tower of Babel in Genesis chapter 11:1–9.