The best way to sample this extraordinary region of marsh and sand dune—short of taking a string of mules and making for the middle of it—is to visit a fascinating village called El Rocío, twenty-odd miles off the road from Seville to Huelva. It is chiefly a place of pilgrimage, for its imposing modern church contains a miraculous figure of the Virgin whose annual fiesta is one of the most colourful events in the Spanish calendar. Half the buildings of the village are white shrines, chapels, hermitages or pilgrims’ hostels: the rest are simple single-storey cottages, and among them there runs a series of wide green swards, shaded by big cork trees. Most of the houses are modern, the village now doubling as pious destination and holiday resort, but the place still possesses a quality of mystery and remoteness: and if this is partly because of the Virgin’s presence there, it is partly because El Rocío stands on the very edge of the Coto Doñana. If you wander down beyond the houses, following the sound of children’s voices, there you will see, beyond the muddy shallows where the small boys play, the swamps, reeds and sand dunes of the great nature reserve stretching away towards the sea.