Pisa is situated on the west coast of Italy, an hour drive from Florence. Pisa of course is known for it's leaning tower. Apparently instead of mothers telling their little 12th century children "Don't play in the sandbox, you'll get your cioppas dirty"...they should have added "and don't build your buildings in them either!". Sadly (well not for the tourist industry) these mothers didn't do this...and their little engineer sons did just that.
They noticed that things were going a little wrong before they finished the third story, so they stopped to ponder the problem for about a hundred years...at this point they decided that modern science had advanced sufficiently to allow them to continue. In this, they were completely incorrect.
They might have worried about this whole leaning problem more, but they were a little occupied about all the wars they were having with Florence. I can only assume that this was caused by the Medici's having run out of places to build palaces in Florence.
In the mid 15th century our friends, the Pisans, decided that what would set off the jaunty angle of the now six story structure would be a nice little bell tower. I have no real proof that the silt build up in the Arno estuary might have something to do with all that sand under the tower having to have somewhere else to go. Sadly this led to a loss of Pisa's naval supremacy during the middle ages (and let's face it the whole engineering thing was so gone already). However, it did cause a booming tourist trade. I believe this would fall into the category of "if you can't hide emphasize".
In the intervening years the jaunty angle became something more resembling an alarming list. Strangely, they were still letting people up inside. I think if you have a really unstable structure that is falling over what you really want to do is fill it with lots of fat tourists.
Now they don't let people up and they are trying to rectify the problem. I suspect they aren't trying to completely fix it however (see aforementioned booming tourist trade).
Here are some of the things they have been trying. They have weighed down one side with 600 tons of lead ingots. An electroosmosis was carried out on the foundation. I have no idea what that means, but it does sound like an impressive effort...which was sadly ineffective.
They came up with a plan of sticking a bunch of anchors into the ground to act as a counter balance, and freezing the ground with liquid nitrogen. This cunning plan worked a little too well, as the tower then started to move in the opposite direction.
There are also huge cables that are attached to the tower and go over surrounding buildings to some heavy duty machines. The wires were pretty slack when we were there...so maybe these are just laundry lines. Also there was a bunch of engineer type people milling about. So maybe they are holding it up with the shear force of their will.
Strangely none of these rather unsightly remedies show up on postcard renderings of the tower. This leads me to believe that the Pisan graphic artists have PhotoShop, and aren't afraid to use it.
