It is about a walk across centuries, allowing to include better heritage and history(story) of Longvilliers. Documented stages will allow in particular to visit the church St Nicholas' Day, 15th - 16th centuries, classified as "Historic Monument" (starting point), to discover the site and the vestiges of the castle among which the most old(former) go back up(raise) to the 11th century, to let impress by the amazing proportions of the cistercienne barn (classified as "Historic Monument") of the farm of Longueroye, old(former) dependence of the abbey dating the 13th century, and to decipher the site of the old(former) royal cistercienne abbey of the 12th century.