Paraguay's three Itapúa missions are sold as one visit and priced as one ticket: Gs 40.000 if you are foreign, Gs 25.000 if you are Paraguayan, free under twelve, valid seventy-two hours, and good at Trinidad, Jesús de Tavarangüé and San Cosme y Damián. Buy it at whichever you reach first. SENATUR runs all three.
Trinidad is the big one — the largest and best-preserved of the thirty reductions, founded 1706, sandstone ashlar, with the frieze of angel musicians, the pulpit, the font and the sacristy portal still in place, and the plaza, cloister, college, workshops, Guaraní houses, cemetery and orchard still legible on the ground. Two museums sit inside the complex, the Jesuítico and the Lítico. It is open from 07:00 and closes at 17:00 in winter, 19:00 in summer, and from Wednesday to Sunday it reopens after dark for the luces y sonidos walk — 19:00 in winter, 21:00 in summer. Ask at the gate whether a Guaraní guide is on; SENATUR names one, Oscar Veramini, who explains the buildings in his own language.
Jesús de Tavarangüé, 12 km north, is the unfinished one: founded 1685, moved twice, settled here in 1758, and abandoned mid-build when the Jesuits were expelled in 1767. The trilobed Moorish arches of the church front are the thing everyone photographs, and the roofless nave gives you the scale it would have had. Wednesdays to Sundays there is a 3D videomapping show projected onto the stonework, at 19:00 and again at 20:00.
San Cosme y Damián, 90 km west on the Paraná, is the odd and lovely one. Its college is the only one of the thirty still standing; there are twenty-two carved wooden figures inside, several with the original polychrome and one Christ with Guaraní features; and because Padre Buenaventura Suárez built an observatory here in the early 1700s, the site now runs solar telescope viewing by day, 07:00 to 19:30, and night telescope viewing from 19:30 to 21:00, seven days a week. Go at dusk and do both.
Book nothing in advance and none of it needs it — but if you want to check that a night show is running, the one mobile SENATUR publishes is Aldo Insfrán's at Jesús, +595 986 650 487. It is a phone number; there is no WhatsApp anywhere in this operation.