Motorized transportation is prohibited on the water here. From the port you can explore the wetlands in a canoe pushed by a boatman with a pole (AR$300 for up to three visitors) or under your own power in a guided kayak trip. Both need to be arranged in advance in San Miguel before heading down to the park. Guides for canoe trips can be found at the shop next to the chapel on the road out of town.
The visitors center at San Miguel has a nice grassy yard for setting up tents and good bathrooms. In San Miguel there are a couple of basic hospedajes as well as an excellent rural lodge.
There's nowhere to buy food or drinks inside the park so even if you're just coming for the day bring plenty of supplies from San Miguel.
In town there are a couple of decent comedores serving up typical fare at reasonable prices.