Located in the village of Santa Maria, it was the mother church of Calanca. It is an important and significant sacred building of mediaeval origin, with precious furnishings: mentioned in 1219, it is characterised by the choir built between 1385 and 1416, the aisle extended in 1606, a round stone gateway and a richly painted coffered ceiling. Three large paintings (17th century), one of which shows the Battle of Lepanto, are noteworthy, as well as numerous wall paintings and valuable painted wooden altars. In the south-west corner of the churchyard, next to the doorway, there is a monumental lime tree, approx. 300 years old, whose trunk has a diameter of approx. 130 cm. The ensemble is rounded off by the Hospice, a rectangular building arranged around an enclosed courtyard with a well, built between the 16th and 17th century on the southern side of the church; previously a Capuchin hospice (1640-1921), it now houses the civil registry offices and contains a hall with Baroque panelling. The tower, strategically located on a high spot behind the church, is an excellent viewpoint with its 30 m height. A remnant of an ancient fortification (13th-14th centuries), the building is pentagonal on the outside and square on the inside, with stairways cut into the thickness of the wall; it is a rare example in the Rhaetian territory of a keep inspired by models from central and northern France.