Parco Rile Tenore Olona, Nature reserve in Castiglione Olona, Italy.

Parco Rile Tenore Olona covers about 1,400 hectares of fluvio-glacial terraces, the pianali morenici, across nine municipalities in the province of Varese. Its geology feeds many small streams from springs and rainwater, alongside broad woods and meadows. The flora is typically Lombard, with Scots pine, pedunculate oak, hornbeam, chestnut, black locust, hazel, plane, ash, red oak, black poplar, elm, maple and black alder.

The park is a protected area of supra-communal interest, formed around the Olona, Rile and Tenore waterways across nine municipalities of the province of Varese, including Castiglione Olona, Gazzada Schianno, Lozza, Morazzone, Caronno Varesino, Gornate Olona, Lonate Ceppino, Castelseprio and Carnago. On 30 July 2015 the municipality of Cassano Magnago decided to join as well. Within the park, in the territory of Castiglione Olona, the Gonfolite and Forre dell'Olona natural monument was established in 2008.

The park's name comes from the three waterways it follows: the Olona river and the Rile and Tenore streams. Inside the park, in the municipality of Castiglione Olona, lies the Gonfolite and Forre dell'Olona Natural Monument, a protected area established in 2008. The planned 165 km Olona Lura cycle route is meant to cross the park and link it with six other local parks along the Olona and Lura waters.

The park is crossed by the planned Ciclovia Olona Lura, a 165 km loop trail linking six other local parks along the Olona river and the Lura stream. The Gonfolite and Forre dell'Olona Natural Monument, a protected area established in 2008, lies within the park in Castiglione Olona.

The name comes from three main waterways: the Rile and Tenore torrents and the Olona River, which flow through the territory from north to south. These three water systems are central to understanding the park's natural structure and ecology.