Lago Huillinco is a striking lake located on Isla Grande de Chiloé in the Los Lagos Region of southern Chile. Part of a remarkable hydrological system, it sits in close proximity to Lago Cucao and is notable for its connection to both freshwater and marine environments — a characteristic that gives it a distinctly unique ecological character compared to typical inland lakes. The lake's waters are influenced by marine intrusion, which shapes its biology from the bottom up and creates fishing conditions unlike those found in most Patagonian lakes. Classified as a free-fishing zone (Tramo de Pesca Libre), Lago Huillinco is accessible to anglers without the need for private access arrangements, making it a worthwhile destination for those exploring the wild and remote fishing waters of Chiloé.