Babel was a city full of riches, gods, power, and strength,  However, their arrogance, pride and sin led them away from God's plan.  It was then that they decided to build a giant towner that would reach to heaven, contradicting God's promise that "He would not destroy the earth again with a flood."  They did not care, and God came down to confuse their tongues, preventing the tower from being finished.

Come, let us go down and confuse their language, so that they may not understand one another's speech." - Genesis 11:7