The Parco di interesse sovracomunale (that is a local Park extending over many municipalities) Alto Milanese has been officially recognized by Region Lombardy's resolution in October 27, 1987 thanks to the suggestion of the three municipalities forming the Consortium: Busto Arsizio, Legnano and Castellanza. The park area extends over 360 hectares, 126 out of which belonging to Busto Arsizio, 178 to Legnano and 53 to Castellanza.
The park is situated between the provinces of Milano and Varese. The Consortium aims at the realization, preservation, maintenance and regulation of the social function of the Park.