Tropical mountain forest Parque Nacional El Imposible was named for the perilous gorge that claimed the lives of farmers and pack mules transporting coffee to the Pacific port. Decreed a national park in 1989, it sits in the Apaneca Ilamatepec mountain range between 300m and 1450m above sea level, and includes eight rivers which feed the watershed for Barra de Santiago and the mangrove forests along the coast.
This original forest – the remains of a threatened ecosystem – is still home to an extraordinary variety of plant and animal life, including pumas, tigrillos, wild boars, king hawks and black-crested eagles. Hiking can get muddy and steep but offers grand vistas of misty peaks and the gleaming Pacific Ocean.
The main San Benito entrance is on the southeast side, beyond the hamlet of San Miguelito. The park is run by SalvaNatura; in theory you need to visit the San Salvador office to pay the entry fee and arrange for guide service (there is no guide fee but a US$5 tip is customary). The best time to visit is October to February, as the rainy season hinders travel.
The solar-powered visitor center has a modest museum and lookout tower with ocean views.