Who designed the Leaning Tower of Pisa?

Answer by  joantheresa (1421)

History states that the Leaning Tower of Pisa was started by Bonanno Pisano in 1173. Work had to be halted because of weak & unstable soil after four years.

Answer by  sususu (866)

No one knows who originally designed the tower, but Giovanni di Simone was associated with the later stages of the tower. The tower was supposed to be straight, but thanks to a badly laid foundation, the tower leaned to the southeast and continues to do so.