It is a national park in the province of Corrientes in Argentina, located near the town of Mburucuyá. It is a highly recommendable place for those interested in wildlife watching, especially birds, mammals and reptiles.
To get to the protected area you take the Provincial Route 6, which is a gravel road, and then take Road 86, which has stretches of gravel and dirt/sand (bear in mind that it can become complicated or impassable if it rains or if it is wet). From the fork it is about 16 km to the recreational part of the park where there is an interpretation centre, a place to camp or spend the day and different trails.
The campsite has parking, wooden tables and benches, barbecue grills, showers and electricity. There is enough space to pitch a tent and spend the night there.
One of the trails called Yatay allows you to take a long walk through palm groves and reach a pier on the shores of the Santa Lucía marshes.