Sanlúcar is the departure for boat trips to the marshes at the mouth of the Guadalquivír River. More than merely scenic, they sustain the Bay of Cádiz shellfishery, and were finally recognized in the late 20th century as one of the most important estuary systems in Europe. They literally keep millions of birds alive as they migrate each year between Europe and Africa. The marshes are also rich with resident storks, egrets, herons, and songbirds. The interpretive center at the Fábrica de Hielo (Ice House) on Bajo de Guia beach explains the marshes, shifting sands, and stabilized sands of the complex ecosystem. The center books 2 1/2-hour riverboat trips into the park, as well as a combined boat and all-terrain vehicle trip to explore different habitats.
- Frommer's Staff