This 24 sq km refuge, not to be confused with the Nicaraguan border crossing of the same name, runs along the steep southern arm of the Cordillera de Tilarán. Elevations here range from 600m to 1400m above sea level, resulting in widely varying vegetation. The terrain is rugged and the place is largely undeveloped for travelers. While there are some hiking trails, they are unmaintained and difficult to follow. The region is inaccessible to all but the most diligent visitors.
The name Peñas Blancas (White Cliffs) refers to the diatomaceous deposits, similar to a good-quality chalk, found in the reserve. The whitish deposits, remnants of unicellular algae once common here when Central America was under water, are found in the steep walls of the refuge’s river canyons.
Peñas Blancas is about 15km northeast of Miramar. Drive east out of town for about 11km to the village of Sabana Bonita, from where you turn north and continue 4km to Peñas Blancas. The road is in rough shape so use your 4WD.