The Arno River is a major river in Italy that flows through the city of Pisa (4 letters) and Florence (8 letters). The Arno River is the most important river in Tuscany and is known for its beauty and historical significance. It is also an important source of water for the region. The city of Florence is located on the banks of the Arno River and is one of the most popular tourist destinations in Italy. It is home to many Renaissance-era monuments, museums, and churches.