The mammoth Parque Nacional Guanacaste protects more than 84,000 hectares of savanna, dry forest, rainforest, and cloud forests extending east from Hwy. 1 to 1,659 meters atop Volcán Cacao.

The park is contiguous with Santa Rosa National Park (to the west) and protects the migratory routes of myriad creatures: jaguars, tapirs, sloths, monkeys, three-wattled bellbirds, and other species, many of which move seasonally between the lowlands and the steep slopes of Volcán Cacao and the dramatically conical Volcán Orosí (1,487 meters), whose wind-battered and rain-drenched eastern slopes contrast sharply with the flora and fauna on the dry plains. Orosí long since ceased activity and, interestingly, shows no signs of a crater.

The park includes significant areas of cattle pasture, which are carefully managed to permit natural reforestation and form an integral part of the migratory mosaic. It is one of the most closely monitored parks scientifically, with three permanent biological stations, all of which offer basic accommodations.

The Pitilla Biological Station is at 600 meters elevation on the northeast side of Cacao amid the lush, rain-soaked forest. It is reached via a rough dirt road from Santa Cecilia, 28 km east of Hwy. 1 beyond Hacienda Los Inocentes. A 4WD is essential. It's a nine-km drive via Esperanza. Don't blithely drive east from Santa Cecilia as that route goes to Upala. Ask locals for the correct route. Cacao Field Station (also called Mengo) sits at the edge of a cloud forest at 1,100 meters on the southwestern slope of Volcán Cacao. It has a laboratory and rustic dorms. You can get there by hiking or taking a horse 10 km along a rough dirt trail from Quebrada Grande (see Quebrada Grande, above); the turnoff from Hwy. 1 is at Potrerillos, nine km south of the Santa Rosa National Park turnoff. You'll see a sign for the station 500 meters beyond Dos Ríos (11 km beyond Quebrada Grande). The road--paved for the first four km--deteriorates gradually.

Four-wheel-drive vehicles can make it to within 300 meters of the station in dry season, with permission; in wet season you'll probably need to park at Gongora, about five km before Cacao (you'll have to proceed on foot or horseback).

Maritza Field Station is farther north, at about 650 meters on the western side of the saddle between Cacao and Orosí Volcanoes. The vegetation here is dry and transitional dry-wet forest. You get there from Hwy. 1 via a dirt road to the right at the Cuajiniquil crossroads. It's 15 kilometers. There are barbed-wire gates: simply close them behind you. Four-wheel drive is essential in wet season. The station has a research laboratory. From here you can hike to Cacao Biological Station. Another trail leads to El Pedregal.

At El Pedregal, on the Llano de los Indios (a plain on the western slope of Orosí), almost 100 petroglyphs representing a pantheon of chiseled supernatural beings lie half-buried in the luxurious undergrowth that cloaks the mountain's hide.

It is one of the least visited and least developed parks in the nation, and facilities are not well developed. The park is administered from the Guanacaste Regional Conservation Area Headquarters at Santa Rosa (see Santa Rosa National Park, above). Entrance: $6.

ARENAL NATIONAL PARK	BRAULIO CARRILLO NATIONAL PARK
CAHUITA NATIONAL PARK	CHIRRIPÓ NATIONAL PARK
CORCOVADO NATIONAL PARK	GUANACASTE NATIONAL PARK
IRAZÚ VOLCANO NATIONAL PARK	JUAN CASTRO BLANCO NATIONAL PARK
PALO VERDE NATIONAL PARK	MANUEL ANTONIO NATIONAL PARK
POÁS VOLCANO NATIONAL PARK	PLAYA GRANDE NATIONAL PARK
SANTA ROSA NATIONAL PARK	RINCÓN DE LA VIEJA NATIONAL PARK
WHALE MARINE NATIONAL PARK	TENORIO VOLCANO NATIONAL PARK