The patron saint of Gravellona Toce is Saint Peter the Apostle, celebrated on 29 June. The parish church dedicated to him was built in the 12th century and later enlarged: the current façade, in neo-Renaissance style, dates from 1862, while the bell tower, from 1865, is built of pink granite blocks. On 9 April 1674, inside the building, the heads of some of the town's leading families gathered and signed the foundation deed of the parish dedicated to Saint Peter.
Gravellona Toce stands at the confluence of the Strona stream with the Toce river, in a strategic crossroads position between the three areas of Verbano, Cusio and Ossola, which favoured the first industrial settlements as early as 1844, such as the Pariani spinning mill, and in 1866 the Furter cotton mill. Having become an independent municipality in 1913, splitting from Casale Corte Cerro, the town also preserves the oldest monumental testimony of the area in the Romanesque church of San Maurizio, documented from the 10th century onward.
