Bordered to the north by the Río San Juan and the frontier with Nicaragua is the vast, 905-square-km (350-square-mile) Barra del Colorado Wildlife Refuge, Costa Rica's largest reserve, and really the only local attraction for nonanglers. Most people arrange trips here through one of the fishing lodges. Transportation once you get here is almost exclusively waterborne, as there are virtually no paths in this swampy terrain. The list of species that you're likely to see
from your boat is almost the same as that for Tortuguero; the main difference here is the feeling of being farther off the beaten track. You can realistically get as far as the 640,000-acre Río Indio-Maíz Biological Reserve when crossing the border here. The reserve is a continuation of the Barra del Colorado Wildlife Refuge, but in Nicaraguan territory.
30 km (18 miles) north of Tortuguero, Barra del Colorado, 70205, Costa Rica
/1192-National Parks hotline in San José