By far the best known sight in Pisa is the famous leaning tower which is but one of many architecturally and artistically important structures in the city's Campo dei Miracoli or Field of Miracles to the north of the old town center.
Pisa was one of the 4 Marine Republics of Italy (Repubbliche Marinare), together with Genoa, Amalfi and Venice. The city was a very important commercial center during the Middle Ages and controlled a significant Mediterranean fleet.
Pisa's Duomo with the Leaning Tower at right
The Pisa is also a river in Poland.