Genesis 11:2-4

And as people journeyed eastward, they found a plain in the land of Shinar and they settled there. [Gen 10:10] They said one to another, “Come, let us make bricks and fire them thoroughly [in a kiln, to harden and strengthen them].” So they used brick for stone [as building material], and they used tar (bitumen, asphalt) for mortar. They said, “Come, let us build a city for ourselves, and a tower whose top will reach into the heavens, and let us make a [famous] name for ourselves, so that we will not be scattered [into separate groups] and be dispersed over the surface of the entire earth [as the LORD instructed].” [Gen 9:1]