The Reserva de la Biosfera Sierra del Rosario is in Pinar del Río province of Cuba. It's not a national park but is a UNESCO Biosphere Reserve. It consists of 25,000 hectares 61,775 acres of the Sierra del Rosario mountains. The principal sites in the reserve are Soroa and Las Terrazas.
Soroa is "off the beaten path" with fewer tourists than Viñales. If you come from Havana you'll welcome getting a full night's sleep in the quiet campo countryside. Las Terrazas is more promoted as a tourist destination.
