Campione was a small Italian enclave in Switzerland, which for a time (1944-1952) issued stamps valid for postage to Switzerland and Italy. These issues were used during the period when northern Italy was controlled by the Italian Social Republic, while Campione remained loyal to the royalist government, from which it was unable to secure supplies of stamps. Stamps were issued in Swiss currency (Francs and Rappen) under authorization it received from the Italian legation in Bern. Oddly, they remained valid long after the war ended, till May 1952.
Four of the stamps in the set of seven pictorial stamps shown below (the 5, 10, 20 and 30 Rappen values) illustrate scenes of the town from the 1940s and the Italian portion of the lake. About a third of the exclave is submerged! The 5 rappen green shows a view over the lake looking south and the 30 rappen blue shows the view to the north.
Since the stamps became invalid, Swiss stamps have been sold in Campione's Italian post office for mail addressed to Switzerland (which is cancelled across the lake at the Swiss post office in Lugano) and Italian stamps are sold for use on mail going everywhere else.