What was used to make the leaning tower of Pisa?

Answer 1

It was the ground that the tower was built on, that eventually caused the tilt of the tower - it was totally unintended. Over the years, there has been many attempts to stabilise the tilt - reinforcing the foundations is just one example. I doubt that anyone wants to see the tower actually fall, or to be straightened to the vertical (the tilted tower is a tourist attraction).

Answer 2

You know the drill; cement, bricks, etc. were used to build up the Tower of Pisa. But because it had been built on a swamp, and nobody knew of that at the time, it gradually began to lean, and probably after the "Grand Opening". 20 Years ago bith Italian and US Scientist's began to try to figure out how to keep The Tower from collapsing. There is a building close to the Tower, and, with the permission of Pisa and the Italian Government, it was agreed to te the Towe ro an adjoining building with extra-heavy duty cables. To this day The Tower still slowly sinks because it was built on swampland. How long before it's gone completely is anybody's guess.