La Boca is a small coastal village in the comuna of Navidad, Provincia Cardenal Caro, O'Higgins Region, situated at the mouth of the Río Rapel where the river meets the Pacific Ocean.

It lies near the boundary with the Valparaíso Region, roughly 4 km from the town of Navidad and about 187 km from the regional capital, Rancagua.

The settlement functions primarily as a tourist destination, drawing visitors to its beach, the river mouth, and the nearby Laguna El Culenar.

Popular activities include windsurfing, kayaking, stand-up paddleboarding, sport fishing, and birdwatching along the riparian and coastal habitat.

An official vehicular and pedestrian access route to the beach has been formally established under Chilean national land regulations, improving entry for both locals and visitors.