Three rivers -- the Cuero, Salado, and San Juan -- feed this massive estuary that is one of the most important natural reserves in Honduras. Since wildlife is abundant, with just a little luck, you will see a decent selection of birds and mammals. There are almost 200 species of birds on record in the reserve, as well as sloths, ocelots, jaguars, otters, howler and white-face monkeys, iguanas, caimans, and the elusive West Indian manatee.
The reserve is nearly impossible to find on your own, even if you're a seasoned guidebook writer. (It can be done with lots of stopping and asking the locals, though.) The best way to explore the canals and mangrove forests is by boat from the visitor center in Salado Barra. Two-hour motorboat tours are standard and explore the canals nearest the visitor center, although some longer tours are available and have a much better chance of encountering manatees. Going with a tour operator (L760-L950) such as Garífuna Tours (tel.504/2440-3252; www.garifunatours.com) or Omega Tours (tel. 504/2440-0334; www.omegatours.info) is a much easier way to see the park (they provide transportation) and far cheaper, in most instances. If you are going on your own, you will have to fork over money for admission, plus the entire cost for the boat and guide, rather than splitting it.
Considering wildlife-watching is best done at dawn, you might want to stay the night at the visitor center's dorm lodging, which runs from L135 per person, or pitch a tent (L55) on the premises of the park. There's a small cafeteria by the visitor center.