Mazagón sits at the northwestern edge of the Parque Nacional de Doñana, a vast complex of marshland, dunes, and pine forest that covers around 540 square kilometres between the Guadalquivir estuary and the Atlantic. It is a UNESCO World Heritage Site and one of the most important wildlife reserves in Europe.
The park itself is largely off-limits to casual visitors — only guided 4x4 tours from El Acebuche or boat tours from Sanlúcar de Barrameda are permitted in the core area — but the surrounding natural park (Espacio Natural) is open and easier to explore. Walking and cycling trails lead from El Acebuche into the cork-oak woods, where you can spot deer, wild boar, and a vast cast of birds: flamingos, spoonbills, egrets, eagles, and the occasional ibis.