The Limoncito Wildlife Refuge is a small protected area on the southern fringes of Puerto Limón, established by decree in 1994 and managed under the Caribbean La Amistad Conservation Area. It is not a national park and has none of the infrastructure: no visitor centre, no marked trails, no entrance booth. What it has is a patch of lowland wetland and forest holding on against the expanding city, and a bird list that includes the boat-billed heron, anhinga, and several species of kingfisher.
Visit with a local guide if you want to make sense of it; trying to wander in alone is unrewarding and the ground is wet for most of the year. The most accessible viewing is from the perimeter road, particularly at dawn.