On this Pentecost weekend, 16,000 pilgrims will leave the square in front of the Saint-Sulpice church in Paris to walk to Beauce. In the heart of a plain of France, the column of pilgrims unfolds towards the cathedral of Chartres.

Charles Péguy sang this landscape, "ocean of wheat", "moving foam" That was in 1912. More than a century later, the atmosphere seems immutable. On the horizon, above the ears of wheat, the two arrows of the religious building point to the sky.