The name of this huge wilderness area translates as the International Friendship Park and derives from the fact that it extends into neighboring Panama. The Costa Rican portion accounts for about half of the total area and is in itself the largest protected area in the country with more than 190,000 ha.

The majority of the park's territory is in the province of Limón on the Caribbean side of the Talamanca Cordillera. However, this sector of the park is very difficult to reach, thus, all three existing ranger stations are located on the Pacific side of the ridge. Hiking into the park from any of these entrances will bring you through a variety of life zones as you continue uphill. Lower montane wet forest, characterized by impressive oak forests where Resplendent Quetzals dwell, is one of the principal habitats encountered on the way up to the higher peaks where low-growing paramo vegetation occurs on the highest summits along the ridge. For the most part, though, the trails through this region are not well-marked.

Given the immense size of the park and the variety of life zones it contains, it has been estimated that at least 60% of all the animal species in the country, from termites to primates, can be found within its boundaries. (The only problem is getting to the boundaries and then beyond.)

Getting there: All three ranger stations are located on the southern slopes of the Talamanca Cordillera. From San José, take the PanAmerican Highway south beyond the town of Buenos Aires to the Paso Real ferry crossing over the Río Grande de Térraba. Once across the river it is only a few kilometers to the Potrero Grande turnoff which leads eventually to the Helechales guard post, 14 km. past Potrero Grande. Four-wheel-drive will likely be necessary on this last stretch.

To get to the other two stations, ignore the Potrero Grande turnoff and continue on the paved road to San Vito. Drive northeast out of San Vito to the Las Mellizas ranger station, about 40 km. There is public bus service from San Vito to Las Mellizas.

The La Escuadra ranger station can be reached by driving north out of San Vito toward the village of Santa Elena (there is also public bus service this far) and then hiking to the village of Agua Caliente and the remaining 14 km. to the guard post.

Climate: The climate is cool and damp at all three of the park ranger stations, and gets colder as you hike up to the top of the ridges. February and March are the driest months.