Its name surfaces for the first time in 1186 and indicates an area of level ground following the rocky nature of the valley to the south.
At one time it served as the principal town of the area, due partly to the hydrotherapeutic treatments it offered during the last century (19th); today it's a popular tourist resort both in summer and winter. It's here in Campodolcino that MUVIS - the museum of the Via Spluga and Val San Gioacomo is situated.
Just to the north of the Parish and spanning the Rabbiosa torrent is the so-called ''Roman bridge'' with its two arches - rebuilt in the 17th century.
It's believed that Portarezza was once the site of a Roman church, whilst today it hosts the church dedicated to San Gregorio Taumaturgo, (the Healer) dating from 1737.
