Nuestra Señora de Loreto, Jesuit mission ruins in Misiones, Argentina

Nuestra Señora de Loreto is a Jesuit reduction ruin in the village of Loreto, Candelaria Department, Misiones Province, Argentina. Its surviving structures are built of rectangular blocks of reddish-brown stone: on the left a wall of stacked red stones stands several courses high, and to its right broad, uneven stone steps descend toward the foreground, with grass growing between the lower tiers. Vegetation has overgrown the site and left it less preserved than San Ignacio Miní.

The mission was founded in 1610, making it one of the earliest Jesuit reductions in the then Province of Paraguay under Spanish colonial rule. After the Jesuits were expelled from South America in 1767, the settlement was gradually abandoned and fell into ruin.

The printing press was built at the mission by Fathers Juan Bautista Neumann and José Serrano, using local wood for the frame and lead-tin type. It was itinerant, set up at Loreto, Santa María la Mayor or San Javier as work required. Its first publication was the "Martirologio Romano" in 1700; Father Antonio Garriga's c.1713 book was the second-oldest printed here.

The site sits in the small town of Loreto and receives fewer visitors than the nearby San Ignacio Mini, which makes for a calmer walk through the grounds. A guided visit is worth considering, as the vegetation covers many structures and on-site signage is limited.

The Loreto ruins are part of the UNESCO World Heritage listing that covers several Jesuit reductions in the region, yet they are considered the least excavated of the group. Visitors who walk the grounds will find structures still largely swallowed by the forest, never fully uncovered.