Q - What is "The Third Heaven"?

A - It's where God dwells. No one has ever been there other the Jesus Christ, this is not the Heaven we go to when we die!

The first heaven we see by day (the sky), the second heaven we see by night (the stars), the third heaven we see BY FAITH (where God lives).

"I knew a man in Christ above fourteen years ago, (whether in the body, I cannot tell; or whether out of the body, I cannot tell: God knoweth;) such an one caught up to the third heaven" (2 Cor. 12:2)