This is the oldest standing building in Florence. Likely part of city wall in byzantine times.
It is now part of the Hotel Brunelleschi, rooms of this tower go for about €1300+/- a night.
There's a small museum with some ceramics found during the restoration, some as old as the days of the young Florence, or Florentia as it was called, dating back to the first century!
There's an underground level where the ruins of the Roman public baths can be visited.
In the late 1200's it was a female jail, the name of this tower derives from the straw mattresses the inmates used to sleep in. read more