If you choose to stay for a few days, Praia do Forte [1] and the surrounding area offer lots of activities. First and foremost are its palm-fringed beaches, which offer the shelter of crescent-shaped coves and natural pools framed by coral reefs. The clear blue waters of Praia do Papa-Gente—a 20-minute walk north—are perfect for snorkeling (masks and fins can be rented at Projeto Tamar).
You can also venture into the Reserva de Preservação Ambiental Sapiranga (Linha Verde Km 5, tel. 71/3676-0211, 9 a.m.–5 p.m. daily, R$6), an ecological nature reserve consisting of 600 hectares of rivers, lagoons, and virgin Atlantic forest, inhabited by endangered creatures such as the mico-estrela-de-tufos-brancos (miniature white tuffed star monkey) and the preguiça-de-coleira (a type of sloth). Various trails weave through the brush and there are plenty of opportunities for bathing in the Rio Pojuca. Aside from hiking, you can explore the park by renting a Jeep, bike, a horse, or the ultra-popular quadricycle (built for two).
With a canoe, you can paddle around the Lagoa Timeantube, a haven for close to 200 exotic bird species. For more information contact Centrotur (tel. 71/3676-1091) and Odara (tel. 71/3676-1080) located near the beginning of Avenida ACM.
Links:
[1] http://www.moon.com/destinations/brazil/bahia/north-salvador/estrada-do-coco/praia-do-forte