What caused the Leaning Tower of Pisa to lean?

Still standing and better built, but for the foundation, than some of our modern structures.

The land that it is built on is fluvial silt, which is why it was not suitable for the tower. The stabilisation was achieved by slowly removing some of the silt from the higher side of the base.

In theory they could straighten the tower but it would still look a bit wonky; they adapted the build because it was already leaning whilst they were building.

Awesome 👍🏼

Scary climb to the top and back down.