Nature
The Marismas del Odiel Biosphere Reserve is recognised by Unesco as having one of the most outstanding, productive tidal systems in the world. Thanks to its dynamism, it provides a link between marshes, beaches, pine forests, lagoons, forests and dunes.
It is located at the final part of the Odiel river basin, with rich, diverse vegetation; from the marsh itself, to the pines, cork oaks, wild olive trees, myrtle, mastic trees, rockrose and rosemary. The variety and amount of it welcomes wildlife, with residents such as spoonbills, flamingos and terns, who all use it as a breeding ground. A population of osprey also exists, following the recent success of a reintroduction program.

Human activity
The natural wealth of Marismas del Odiel is complemented by its historical and cultural past, which links the marshes and their surrounding lands with ancient Mediterranean and Atlantic trade routes. The result is a socio-economic structure in which uses of the sea are combined with those derived from marshes and land consolidation. Boatbuilding, shellfishing, hunting, and the use of the forest are trades and past times which are deeply rooted among the inhabitants.
In 2017, after its expansion, the Marismas del Odiel Biosphere Reserve began a new phase, complying with Unesco requirements by having a transition zone. The Environmental Administration, the towns and the inhabitants themselves must continue working together for a sustainable future from ventures such as fishing, salt flats, aquaculture, agriculture and birdlife tourism.

Culture
The Marismas del Odiel has been an area of strategic importance for thousands of years and is therefore home to numerous examples of Andalusian historical and cultural heritage such as the Roman salting factory, “almadrabas” (Phoenician fishing), salt marshes, etc.
Additionally, the ethnographically valuable Bacuta salt flats; the traditional shipyard of Punta Umbría, the medieval city ruins of Saltés; the early 20th century Tinto dock which was given Cultural Property status in 2003; the Alfarero tide mill, where flour was obtained to make Aljaraque bread; and the Reina Victoria neighbourhood, which dates from the beginning of the 20th century and was home for the Rio Tinto and Tharsis mine workers.