It is known as Santu Antinu.in the Sardinian language. The rural church of San Costantino, in the territory of Sedilo, overlooks the splendid scenery of Lake Omodeo, the largest artificial basin on the Island (for a long time also the largest in Europe). Along the perimeter of the sanctuary are the buildings used as accommodation for pilgrims, known as cumbessias or muristenes.

The year in which it was founded is unknown but there is certainty regarding San Costantino Imperatore’s very ancient origin. The current building, in Gothic Catal style, dates back to the 16th century and it underwent renovation work in the 18th century. Of the original structure, the quadrangular presbytery still remains and has a ribbed cross vault with suspended capitals sculpted at the base.