Caño Negro Wildlife Refuge, Wildlife refuge in Alajuela Province, Costa Rica

Caño Negro Wildlife Refuge is a mixed wildlife refuge of about 10,171 hectares in the lower basin of the Frío River, split between Los Chiles and Guatuso cantons. Its core is Laguna Caño Negro, a shallow freshwater lagoon of some 800 hectares fed by the Frío and its tributary the Río Mónico. Wetlands cover roughly 3,500 hectares of slow rivers, seasonally flooded grasslands and palm groves.

The Costa Rican government created this refuge in 1984 to protect the region's ecological diversity. In 1991, it gained international recognition as a Ramsar site for its importance as a global wetland.

The refuge's name comes from the dark, tannin-stained water of the Caño Negro lagoon, which gives the site its "black channel" name. Local guides, many from the town of Caño Negro, lead daytime and nighttime walks and boat trips on the Frío River, and bilingual guides can be hired at the SINAC visitor centre.

The refuge lies in the lower Frío River basin, 21 km southwest of Los Chiles and 36 km southeast of Upala; Route 138 links Routes 4 and 35. A SINAC visitor centre with an adjacent pier and walkways, partly wheelchair-accessible, serves as the starting point. Boats, kayaks and canoes explore the Frío River; recreational fishing is closed from April to August, while birdwatching, trails and the observation tower stay open all year.

The refuge shelters the gaspar, a prehistoric fish that surfaces regularly to breathe air. Spotting this ancient creature during visits is an unexpected highlight for many travelers.