This tower's main characteristic is the hanging garden on the roof.
Passeggiata delle Mura
Like Cittadella (where I currently live), Lucca is a walled city. The "Passeggiata delle Mura" is a popular route along the street on top of the walls for runners, bicyclists, and people like myself who just want to enjoy a nice walk.
The Amphitheater Square
This square is built on the ruins of an ancient Roman amphitheater, whose base is now ~3 meters below the center. It is now an urban square, surrounded by private residences and a few outdoor cafes.
Giacomo Puccini's Childhood House
San Michele in Foro
A Roman Catholic basilica dedicated to Archangel Michael.