Lake Maggiore is the second largest of Italian lakes, but may rank first in beauty. It is an internationally famous resort of Europe, with its picturesque and spectacular landscape, mild climate and luxuriant vegetation. The climate favors a beautiful botanic garden on the lake shore, with exotic and rare plants including even those from the subtropical zone. The lake has many islands and some of them are famous for their lovely parks and pretty villas.

L. Maggiore is 65 km long, 2-4.5 km wide and 370 m deep in its maximum depth. Recently, eutrophication has proceeded in part of the littoral zones, and inflowing waste water is now completely treated. More advanced plants with tertiary treatment are under construction. The concentration of inorganic nitrogen in the lake water has increased gradually since 1960. Those of reactive and total phosphorus also increased until 1977, but have since been decreasing. During the past ten years, the biomass and composition of phytoplankton, chlorophyll concentration and primary productivity have been quite stable, most probably as the result of the control of waste water discharge from the drainage basin.