Formosa province's standout attraction is Bañado la Estrella. This stunning wetland area is a floodplain of the Río Pilcomayo and harbors an astonishing range of birdlife, as well as alligators, capybaras, sizeable serpents and beautiful water plants. From the roads that cross this 200km-long finger-shaped area, it's easy to spot a huge variety of wildlife: pack binoculars.
One of the highlights of the park is Fortín Soledad where local residents organize canoe trips among the lush landscapes.
The handiest town for the Bañado is Las Lomitas, 300km west of Formosa on RN81 and accessed by regular bus (AR$300, 5½ to six hours). From here, paved RP28 heads north and cuts across the wetlands on a causeway, starting 37km north of Las Lomitas and extending for some 15km.
In Las Lomitas there is a range of accommodations, the best of which are out on the highway.