Lieutenant Colonel Carmelo Peralta National Airport — Concepción, Paraguay

Along the eastern bank of the Paraguay River, CIO provides a modest air link to Concepción, a trading town whose historic role as a river port once made it one of the country's more significant commercial centers. The airport takes its name from Lieutenant Colonel Carmelo Peralta and handles light domestic traffic rather than any scheduled international routes, reflecting the generally limited scale of aviation infrastructure across Paraguay's interior beyond Asunción. Cattle ranching and agriculture dominate the surrounding Concepción department, and the airfield occasionally sees charter or cargo flights tied to that rural economy. Unpaved surfaces and limited navigation aids have historically constrained operations to smaller aircraft and favorable daytime weather conditions.