This 238-sq.-km (148-sq.-mile) cloud forest park, the first protected area in the country, was named a national park in 1982. Most who visit the park are after one thing: birds. More than 350 species have been identified in the park. Rare species such as the resplendent quetzal, wine-throated hummingbird, and the rufous browned wren, are seen by a lucky few, as are mammals such as pumas, agoutis, and armadillos. Plant life includes pine forests, bromeliads, orchids, ferns, lichens, and mushrooms.

There are eight good hiking trails through the park, as well as two entrances. At the first entrance, at Jutiapa, there's a small visitor center with a few cabins and a small new ecolodge with rooms for rent for L475 per person. Most hiking trails begin from this first entrance; these trails are used by the majority of tourists and are in good condition. The Sendero Principal, the main route through the park that extends 6km (4 miles) from one end to the other, follows what was once the main road for the miners, and has been allowed to deteriorate into a more natural state. Almost all other trails branch off from this one.