Located 20 km north of San José on the road to Guápiles.
It is terrain of rugged mountains, rushing rivers, dormant volcanoes, deep canyons and rainforests. It is also one of the cloudiest places in the country. The rain falls either in torrents or in heavy and persistent drizzles that shroud the land in thick almost permanent banks of fog. Waterfalls plunge down ravines that rend steep mountain slopes, which are carpeted with evergreen rainforest thick with ferns, palms, epiphytes, and carrizales, especially between 1,500-2,500 meters above sea level. Farther on, in the land of the volcanoes, muffled in fog and battered by the wind, the forest is dark and extremely humid with tall trees and an abundance of mosses and bromeliads. It is the home of the resplendent Quetzal, considered to be the most beautiful bird on the continent and symbol of the currency of Guatemala, a country with dwindling populations of this species.
The park consists of 44,099 hectares with an unusual wealth of flora and fauna. This is caused, in part, by a wide variance in rainfall (from 2,500-8000 mm a year) in temperature (from 9 to 25 ºC) and altitude: the park protects a vast region, from lowlands near the northern plains, at 200 meters above sea level, to the rim of Barva Volcano, at 2906 meters above sea level. In the highlands the most distinctive trees amid a lush foliage, which includes over 6000 species, are oak, mountain cypress, small cedar and magnolia.
Typical vegetation in the lowlands includes olive, alcanfor, mayo and copal. In clearings above 1,400 metres, a common plant is that known as poor man's umbrella with very large, rough leaves typical of highly saturated areas. Apparently, it is a way of exposing a larger surface to the sun, thereby increasing the rate of transpiration.
The rainforest provides shelter for an infinite number of animals from the bushmaster sanke, the largest poisonous snake on the continent, to the Bufo holdridgei toad, an endemic species that lives in communities on Barba Volcano and at Bajos del Tigre.
Below 1000 metres, it is frequent to see howler and white-faced monkeys capuchin monkeys, tapirs, ocelots, cougars, jaguars, jaguarundies, white-tailed deer, pacas, agouties, racoons, white-nosed coaties, kinkajous, grey squirrels, Southern opossum, two- and three-toed sloths and five species of bats. The birdlife consists of over 350 species, which include the strange three wattled bellbird (which migrates at great hights), king vulture, great curassow, clay-colored robin (the national bird), solitary eagle, black-faced solitaire and resplendent quetzal.
The most suitable time to visit the rainy highlands (1,500 mts. and up) is March and April, when it is sunnier and warmer.