Is the famous hanging tower to make Pisa well know in all over the world; but this city offers much more and really deserves a on-day visit. 
Reaching the stunning “Piazza dei Miracoli”, your look is immediately captured by the tower and the experience of walking until the top is incredible and amazing (you can purchase the tickets in advance).
Once you enjoyed the Tower from every corner, just go on with your visit to the other monuments of the square: the Cattedrale and the Battistero. Along the square you will find as well the Camposanto, the “Opera del Duomo” museum and the “Sinopie” museum. 
Then, enjoy a nice walk along the river Arno and reach the ancient “Palazzo dell’Orologio” and Cavalieri square, once the center of the city power and then headquarter of the “Ordine Cavalieri di Santo Stefano”. In the “Palazzo della Carovana” there is the eminent “Scuola Normale di Pisa”.
On more thing from Pisa you cannot miss? The Cecina! A kind of savoury pie, very thin, made only with chickpeas flour, oil, salt and water. Really delicious!