This idyllic park, centered around the Cerro San Gil mountain, comprises more than 7,700 hectares (19,000 acres) of lush rainforest. Bathed in rainfall throughout most of the year (averaging 255 inches) as warm, humid air rises over the mountains from the sea to elevations in excess of 1,100 meters (3,900 feet), the preserve harbors an astounding level of biodiversity.

Among the wildlife protected here are 56 species of mammals, including tapir and jaguars, 50 species of reptiles and amphibians, and more than 350 species of birds, including toucans, black and white hawk eagles, and keel-billed motmots. More than 90 neotropical migrants winter in the area and include the blue-winged warbler and wood thrush.

The park also protects the important watershed of the Río Las Escobas, which supplies water to Puerto Barrios. Part of the watershed is open to visitors ($8, including guided tour), who can bathe in Las Escobas’s cool, clear waters and hike a series of nature trails winding through the park.

The park is administered by private conservation group FUNDAECO (tel. 7948-4404, www.fundaeco.org.gt), which in partnership with The Nature Conservancy has been able to buy large tracts of this rainforest ecosystem for preservation.

Facilities for visitors are found at Las Pozas (tel. 5708-0744 and 5004-1143, www.riolasescobas.com, 9 a.m.–6 p.m. daily) and include a visitors center, tropical gardens, a snack bar (open on weekends and when cruise ships are in town), and picnic areas. An excellent system of trails winds through the river and waterfalls and includes wooden bridges with stops along the way for swimming in stunning turquoise pools.

More adventurous types can explore areas deeper into the reserve beginning at a trailhead just up the mountain and going from there to the Río Las Escobas through a dense stretch of forest (one hour) or to Cumbre Las Torres (four hours there and back), or encompassing multiple days of strenuous jungle hiking to the village of Carboneras and down the mountain to Río Dulce.

Contact FUNDAECO if you wish to explore these options, as you will need prior authorization. A guided trek of either of the first two options costs $20 per person. Rates for the longer trip are negotiable.

The park is an increasingly popular day trip with cruise-ship passengers, many of whom reportedly state this to be their favorite stop after the crass commercialism of places such as Cancún and beaches that all pretty much look the same. The park lies just off the road, hugging the coastline from Puerto Santo Tomás de Castilla to the beach of Punta de Palma Beach.

Antigua-based Chiltepe Tours (7a Calle Poniente #15, Centro Comercial El Búcaro, Antigua, tel. 5907-0913) is a Gray Line affiliate offering jeep tours from the cruise-ship terminal to Río Las Escobas in fully restored American M151A2 jeeps with quarter-ton trailers hitched on to the back. The trips leave the cruise-ship terminal hourly at the bottom of the hour starting at 8:30 a.m., taking about 30 minutes. You can stay as long as you like at Las Escobas, with the last jeep heading back to the cruise-ship terminal at 4 p.m. Other return trips from Las Escobas leave hourly at the top of the hour. The tour costs $39 (adults) or $34 (children).