Santa María la Mayor, Jesuit ruins in Misiones Province, Argentina.

Santa María la Mayor is a ruined Jesuit reduction near the village of La Corita in Santa María, Misiones Province, reached by Provincial Route 2 along the Uruguay River. Its stone walls and earth structures are overgrown by vegetation and less well preserved than those of San Ignacio Miní. A visitor centre serves the public and researchers.

Founded in 1626, the mission grew into an important center of learning and craft. It operated until 1767 when Spanish authorities expelled the Jesuit order from their colonial territories.

The place reveals how a community gathered around Jesuit teachings while maintaining its own language. Guarani remained spoken and written here, shaping daily life and religious practice.

The site sits within a protected natural reserve and can be explored with a guide. Bring sturdy walking shoes and be prepared for uneven terrain and changing weather conditions.

Nicolás Yapuguaý was born and lived in this reduction. A Guarani cacique, he read Spanish, Guarani and Latin, taught Guarani to the Jesuit priests, and wrote the kinship tables of several Guarani groups, which led some researchers to call him the first social anthropologist of the Río de la Plata area. His surname means "the truthful one".