From the Wikipedia page 
The Mendrisio District (Italian: Distretto di Mendrisio, also called Mendrisiotto) is the southernmost district of canton of Ticino and of Switzerland. To its north lies the Lugano District. It is surrounded on the other three sides by Italy: to the east and south by the province of Como, and to the west by the Province of Varese. It has a population of 51,564 (as of 31 December 2016).