Locarno is a city located on the northern tip of Lake Maggiore (Lago Maggiore) in the southern Swiss canton of Ticino, close to Ascona. It has a population of about 15,000. An important film festival, the "Festival Internazionale del Cinema di Locarno", takes place every year in August in the Piazza Grande. The Locarno Treaties were negotiated here in 1925.

In January 2004, the Italian historian Marino Vigano speculated that Locarno's castle may have been designed by Leonardo da Vinci.