The Catedral Nuestra Señora del Rosario sits at the head of Plaza 1° de Mayo, the heart of the old city. The current building dates from the 1880s, an Italianate basilica with twin towers, a large central dome, and a richly decorated interior — marble columns, gilded altars, paintings from the late 19th century. It is the seat of the Archdiocese of Paraná, raised to that status when the city was briefly the capital of the Argentine Confederation in the 1850s.
The plaza itself, with its tall palms, the cathedral on one side and the colonnaded Casa de Gobierno on another, is one of the best provincial squares in Argentina. Late afternoon, when the heat has dropped, is the moment to visit.