The Quadrilatero (English: Quadrilateral, for greater specificity often called the "Quadrilateral fortresses") is the traditional name of a defensive system of the Austrian Empire in the Lombardy-Venetia region of Italy, which connected the fortresses of Peschiera, Mantua, Legnago and Verona between the Mincio, the Po and Adige Rivers. The name refers to the fact that on a map the fortresses appear to form the vertices of a quadrilateral. In the period between the end of the Napoleonic Wars and the Revolutions of 1848, they were the only fully modernized and armed fortresses within the Empire.