The lake is 48.7 km2 in size, 63% of which is in Switzerland and 37% in Italy, has an average width of roughly a kilometer, a maximum depth of 288m found in the northern basin and bathing in the lake is allowed at any of the 50 or so bathing establishments located along the Swiss shores. The Italian waters of the lake and the exclave of Campione d'Italia are considered by Italian law as non-territorial for fiscal purposes and as such enjoy a special tax status as a duty free area, exemption from EU VAT and offer residents other advantageous tax privileges.
The whole area behind the southern shores of Lake Lugano is rich in fossils. The focal point of these fossil deposits is Monte San Giorgio, where since the 19th century many fossils have been found dating from the mid Triassic (around 220 million years ago). The deposits on Monte San Giorgio stretch towards the west into Italian territory and the deposits of Besano. 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.