The origin of the lake Maggiore (or Verbano) is glacial, testified by the disposition of the hills formed by morainic deposits of glacial nature, the profile of the lake has the typical form to V of the river valleys. Its surface bathes for 80% Italy (provinces of Novara, Verbano Cusio Ossola and Varese) and for 20% Switzerland (Canton Ticino), it is one of the principal alpine lakes and the second greatest lake in Italy, after that of Garda. The principal tributaries are the Ticino, the Toce, the Tresa and the Maggia, those smaller are the streams San Bernardino, Cannobino, Verzasca, Margorabbia, Giona and Boesio.

The lake Maggiore is characterized by the presence of famous islands and islets, shed in Piedmont (8), in Lombardy (1) and in Switzerland (2). More characteristics are, also for historical importance, in the Gulf Borromeo, in Piedmont between Stresa and Verbania: the island Madre, the island Bella, the Pescatori's island or Superiore, the islet La Malghera and the island San Giovanni; continuing to north, in front of Cannero Riviera, the three small Cannero islets or Malpaga; in Lombardy, in the south of the lake, in front of Angera the small islet Partegora; in Switzerland, in front of Brissago, the two Brissago islands.