Beneath the church and adjacent chateau in Habarcq lies an ancient chalk mine. Many of the buildings in the village use chalk blocks for their walls. It is likely that the space was used as a mediaeval Muches ie a shelter for villagers during the Franco Spanish war as some access steps appear to post-date the quarrying.
In World War I, parts of the quarry were strengthened and used as an Allied headquarters; grafitti from this period is still in evidence. In World War II the Chateau was used as a German headquarters. The quarry was allegedly unknown by the Germans until a German tank fell through the ground in front of the chateau.