Puerto Viejo de Talamanca is 12 km south of Cahuita and operates at a different register entirely. Where Cahuita is quiet and village-scale, Puerto Viejo has a proper backpacker strip, a clutch of bars that stay open late, restaurants from several different culinary traditions, and a surf break — Salsa Brava — that is one of the heaviest reef breaks in Central America. The wave breaks over shallow coral and is strictly for experienced surfers, but watching it from the shore is worthwhile regardless of ability.
The road south from Puerto Viejo towards Manzanillo passes some of the best beaches on the coast: Playa Cocles and Playa Chiquita are long, relatively uncrowded, and backed by jungle. A bicycle makes the most sense for this stretch — the road is mostly flat and the distances are manageable. Puerto Viejo itself makes a reasonable day trip from Cahuita if you want a livelier evening, or a longer excursion if you combine the town with the beaches to the south. The local buses between Cahuita and Puerto Viejo run regularly through the day.