Lago Vichuquén is a coastal lake situated in the comuna of Vichuquén, Provincia de Curicó, in Chile's Maule Region. It lies at roughly 2 meters above sea level and covers approximately 40 square kilometers, stretching about 18 kilometers at its longest point. The lake is separated from the Pacific Ocean by a narrow strip of dunes and forest, and it connects to the sea via the Estero de Llico. The nearby settlement of Llico and the town of Vichuquén, located about 8 kilometers away, are the principal inhabited centers in the area. The lake's name derives from Mapudungún and is associated with sorcery and the supernatural; a small community called Aquelarre sits on its shores, reflecting this cultural heritage.

The lake is accessible by land via Route J-60 from Curicó, continuing on Route J-80. Because the water is shallow overall, it warms considerably during summer, making it a popular destination for water sports including kayak, sailing, windsurf, water-skiing, and sport fishing. The best months for paddling and other water activities are generally October through April, aligning with the dry Mediterranean season. Summer high temperatures range from 19°C to 30°C, while winter minimums drop to around 7°C.

Black-necked swans are a common sight on the lake, and the adjacent Laguna Torca is a protected natural reserve worth noting for wildlife observation. The surrounding landscape combines dunes, coastal forest, and rural agricultural land. Panoramic viewpoints and trails in the area offer views of both the lake and the Pacific Ocean.

Facilities and tourist infrastructure are available, including accommodation, food services, camping, and organized boat excursions. Nearby attractions include the beaches of Iloca and Duao, Llico Bay, the Torca Lagoon National Reserve, and the town of Vichuquén itself, which has been designated a Zona Típica for its preserved colonial architecture and houses a local museum. The lake draws significant visitor numbers from Santiago and Talca during the summer season, so paddlers should expect increased boat traffic and activity on the water during those months.