Mastellina is another hamlet that has preserved its traditional features, one of whose best examples is the so-called Casa Guardi, native house of the family of the painting genius Francesco Guardi.
The first evidences of a place named de Mastalina date back to 1220. The toponym coming from the medieval Latin word mastellum apparently refers to the presence of small hollows in the ground. The village used to be part of the Comunità della Commezzadura. The ancient church dedicated to Saint Anthony the abbot as well as the nearby hospice, whose existence is evidenced since the mid 16th Century were subject for a period to the prioral church of Saint Mary in Campiglio. Between 1819 and 1928 the village was an independent town and later became part of Commezzadura.
The 15th Century church dedicated to Saint Anthony the abbot was restored and enlarged in 1607, when the late Renaissance portal was added on the façade. The small building is sided by a un curious bell tower with a stone pyramid roofing and four side pinnacles. In The interior houses some frescoed paintings attributed to Giovanni and Battista Baschenis (1483; 1489). The 17th Century main altar casket boasts three statues coming from an old late-gothic altar and attributed to the workshop of Narciso da Bolzano (in the last decades of the 15th century).
The hamlet houses the native house of the Guardi family where, in 1678, was born Domenico, father of the famous painters Francesco and Giovanni Antonio. The building boasts a beautiful portal with a round arch whose keystones are decorated with a serpentine motif. Right of the entrance there is a wall painting portraying the Madonna with Infant Jesus between Saints James and Peter. The house was visited by Francesco in 1778 and in 1782, when he came up to Val di Sole from Venice.