The dune of Pilat is considered a foredune, meaning a dune that runs parallel to a shoreline, behind the high tide line of a beach. The dune has been observed to move landward, slowly pushing the forest back to cover houses, roads and portions of the Atlantic Wall. To back this evidence of coastal movement, maps from 1708 and 1786 both place areas with the name Pilat to the south and off-shore of the current dune's location.