A large village situated 4 miles (6 km) south of Saint-Omer, at the D195 and D198 crossroads.
It is located on a geological formation called the "plateau d'Helfaut", which separates the Aa valley to the north from the Lys valley, to the south. The commune is home to a unique geological heritage, resulting in an unusual landscape. The sides of the old quarries alongside the plateau display many geological strata. The quarries of Heuringhem and Blendecques have collapsed as a result of soil creep. The commune gave its name to 'Dilluvium d’Helfaut', a flint and clay formation rare in France and Europe.
The commune is home to many rare and protected species in a heathland landscape, which is unusual for northern France and justified the creation of a nature reserve (Les Landes d'Helfaut).
The village was subject to much damage during World War II, as it was here that the Germans sited La coupole, an underground bunker, housing a huge concrete dome built by the Nazis between 1943 and 1944. Initially this bunker was to serve as a base to launch V2 rockets, but it never entered service because of the many bombing raids by the Allies. The Dome has been transformed into a museum.[5]
Places of interest
The church of St. Fuscien and St. Victoric, dating from the thirteenth century.