As reported elsewhere, this is a difficult site to access. I reached the entry point at La Rocina by bus from Seville via the sand dunes of Matalascanes. From this entry I follwed the boardwalks to hides along the Madre de las Marismas.

I returned from El Rocio to Seville via Almonte, but another time I would avoid the summer weekends when the buses are full of people going to the beach.