The tower was Built with 14,500 TONS! - just to have enough support to lean and still stand.
And get this! AFTER the second floor was under construction, they realized that the foundation was too soft to stand tall and straight .
Inside the tower there are seven bells, each one representing a note on the major scale.
All placed on the eight floor. Sadly, no elevators! But really good exercise if you plan to visit.
The fact whether it should go straight or still keep on leaning is still a debate, but how can you call a tower a leaning tower if it is not leaning?