Chigualoco is an access point on the Estero Chigualoco, a small coastal stream in the Coquimbo Region of Chile, situated just south of the lower course of the río Choapa.

The estero drains a basin of roughly 90 km² and reaches the sea at Bajos Chigualoco at an elevation of about 7 meters. The stream follows a strictly rain-fed regime, carrying water only during periods of rainfall along the coastal strip.

The estero's mouth area has been noted as a birdwatching locality and as a coastal wetland of ecological interest, with its sediments studied in the context of broader research on Chilean coastal wetland systems.