Occupying an area of strategic importance, the lake was then part of the feudal dominion of the County of Sperio.

[1] The lake definitively ceased to belong to a single sovereign political entity following the establishment of the transalpine bailiwicks of the Swiss cantons at the beginning of the 16th century.

The culminating point of the lake's drainage basin is the Pizzo di Gino summit in the Lugano Prealps (2,245 m; 7,365 ft).

[4] The Italian exclave of Campione d'Italia and parts of the waters of the lake are considered by European Customs Law as non-territorial for fiscal purposes and as such enjoy a special tax status as a duty-free area, exemption from EU VAT[5] and offer residents other advantageous tax privileges.

Bacteria can cause in the worst case, skin infections, diarrhoea and vomiting.According to Legambiente, the only reason swimming was not banned on the Italian Lakes was because the state of Lombardy changed the law.

They state that pollution levels in the lakes do not conform to European rulings and the lack of sewage treatment is illegal.

The bleak is almost extinct here, unlike in Lago Maggiore, and planning is under way for the controlled repopulation of the lake, particularly around Ponte Tresa.

Since 1950 attempts have been made to introduce the whitefish Coregonus macrophthalmus from Lake Neuchâtel, but it has not established itself effectively.

The Common Roach is present in large numbers and took around ten years to colonise the entire lake, thereby replacing the bleak.

Fossils dating from the early Jurassic (around 180 million years ago) have also been found along the southern shores but more towards the east and Osteno.