Carara National Park

This park is less than 10 miles north of Jaco beach. Carara Biological Reserve has several miles of trails through primary rainforest where you can look for wildlife, early morning and late afternoon being the best times. You can expect to see caiman and the endearing white-faced capuchin monkeys. There are lots of birds here including a large number of eye-catching scarlet macaws that rest in the mangroves. In the north you can take boat trips on the Tarcoles River to view crocodiles. 
Reasons to include Carara Biological Reserve include:

• The park has an enormous diversity of flora and fauna an dis one of the few places where you can see scarlet macaws.
• Carara National Park contains several different ecosystems, from marshlands to tropical and dry forests which are home to an array of wildlife.
• Carara is popular with birders, get here early for the best birding.
• Monkeys, crocodiles, armadillos and more inhabit the reserve, as well as a vast number of bird species. The thick canopy can make it harder to spot them, but you can hire a guide to accompany you.
• Head for Rio Tarcoles Bridge where you can view the crocodiles, also you may see scarlet macaws here if you're lucky.
• There are several archaeological sites in the park, dating back over 2000 years to pre-Columbian times.
• Hiking here is relatively easy with a variety of trails 1-2km long, and all are reasonably flat.