Mission São Lourenço Mártir, Archaeological site in São Luiz Gonzaga, Brazil.

Mission São Lourenço Mártir is an archaeological site in Rio Grande do Sul that preserves the remains of a Jesuit settlement. The location contains fragments of a church building, burial grounds, and residential areas that reveal how the community was laid out.

Jesuit missionaries established this settlement in 1690 and it grew into a significant community with thousands of inhabitants. The mission expanded over time to become one of the larger settlements of its kind before external events led to its decline.

The Jesuits made the Guarani into specialised labour: the mission economy was self-sufficient and produced surpluses, with yerba mate and cattle raising as its main activities. Mate was promoted by the priests to replace alcoholic drink. To motivate work, the missionaries organised games, team tasks and championships, drawing on Guarani collectivism.

The site can be explored on foot to view the scattered ruins and burial grounds across the grounds. Wear sturdy shoes and watch for uneven surfaces as you move through the archaeological area.

The site lies 30 km from São Luiz Gonzaga, reached by the BR-285. Excavations have revealed a water network that supplied the mission, alongside kilns for mud bricks and roof tiles and a tannery on the outskirts. Few church walls remain standing, but they still show the building's size.