Santa Rosa was founded in 1698, established by the Jesuit father Jacobo Ranzonier together with the Guaraní, and settled in part by families who came from the nearby town of Santa María de Fe. It belonged to the famous network of reductions that the Society of Jesus organized across the Province of Paraguay, semi-autonomous mission towns where Guaraní communities lived, farmed, worshipped, and made art under Jesuit direction. The town took its name from Santa Rosa de Lima, the seventeenth-century Peruvian woman who became the first person born in the Americas to be canonized a saint. Long after the Jesuits were expelled from Spanish America in 1767, the shape they gave this place endured in its streets, its devotions, and the red stone of its surviving monuments.

The jewel of Santa Rosa is the Chapel of Our Lady of Loreto, built around 1706 and named for a Marian devotion carried from Italy. When the main church burned in 1883, the chapel came through, and inside it the colonial world is astonishingly intact. The walls and the wooden ceiling still hold their original frescoes, including a celebrated depiction of the Annunciation, painted by Guaraní artists who had been trained in the European styles of the day but worked with their own hands and eyes. Stars still spread across the painted ceiling, untouched since the eighteenth century. Beside the central square rises a campanile twenty meters tall, built in red stone, one of the most important structures left from the mission era.

Santa Rosa keeps its older stories close to the surface. In the Plaza Mariscal Estigarribia, the artist Koki Ruiz carved a fountain ringed with figures from Guaraní mythology, among them the Kurupí, a forest spirit of folk belief. Out near the hill stands the Itá Balanze, a great block of stone said to rock on its base, and the Pombero Pyporé, a stone held improbably upright where, the story goes, you can find a footprint left by the Pombero, the mischievous night-spirit of the Paraguayan countryside. The town's museums, the Jesuit Museum and the museum housed in the Loreto Chapel itself, gather the relics of that vanished world, while old colonial buildings around the square have quietly become shops. In summer the Sangurí stream fills with people escaping the heat that can climb toward 39 degrees Celsius. The land around is cattle country, broad ranches and farmland under a sky that runs to the horizon.

Santa Rosa belongs to the Misiones department, a name that is itself a memorial: this whole region of southern Paraguay is named for the missions that once organized life across it. When the Spanish crown expelled the Society of Jesus from its American territories in 1767, the reductions lost the priests who had run them, and the towns slowly changed hands and changed character. Yet Santa Rosa never disappeared. It carried its mission architecture, its saints, and its devotions into the centuries that followed, surviving fire, war, and the long decline of the empire that founded it. Today it is a working district of roughly 20,000 people, and a visitor walks the same plaza the Guaraní laid out, beneath a bell tower that has watched over it for more than three hundred years.