The stone shell of a lost missionThe Ruins of São Miguel Arcanjo, known in Brazil as the Ruínas de São Miguel das Missões, are the remains of a Guaraní-Jesuit mission in the northwest of Rio Grande do Sul. From the air the plan of a whole vanished town is legible in the grass: the great roofless church at the centre, the lines of the plaza and the workshops and dwellings around it, laid out to an ordered design that was advanced for its place and time. A Guaraní-Jesuit reductionSão Miguel was one of the Sete Povos das Missões — the seven mission towns the Jesuits founded east of the Uruguay river when the territory was still Spanish. The reduction was built from 1687, and there a self-governing community of thousands of Guaraní grew prosperous, blending European and Indigenous traditions in a flowering of music, craft and architecture. Its great stone church was raised between 1735 and 1750. War, ruin and rediscoveryThe mission's decline came almost as soon as it reached its height. Caught in the territorial disputes between Portugal and Spain, São Miguel became a centre of the Guaraní War and was burned and depopulated in 1756; after the Jesuits were expelled and their order suppressed, it was looted and finally abandoned in the early 19th century. Conservation of the ruins began in 1925. The site was protected as national heritage by IPHAN in 1938 and inscribed by UNESCO as a World Heritage Site in 1983, together with four sister mission ruins across the border in Argentina.Today the church's surviving façade and walls are among the most recognisable images of Rio Grande do Sul, and the nearby Guaraní communities hold the place as sacred — a ruin that is also a living site of memory.