The city of Corrientes sits directly across the Río Paraná from Resistencia and the two are linked by the General Belgrano Bridge — a regular bus crossing takes about 30 minutes. Corrientes is older, prettier and more obviously colonial than Resistencia, with a low historic centre, riverfront walks along the Costanera, and the country's most famous Carnival outside Gualeguaychú.
A day trip to Corrientes is the obvious first move from Resistencia. Combine with lunch at one of the riverfront restaurants and a walk along the Costanera at sunset. The Paraná is wide, brown and full of dorado fishermen.