Caix is a commune in the Somme department in Hauts-de-France in northern France. Its 13th-16th century church is a listed monument. …Caix is a commune in the Somme department in Hauts-de-France in northern France. Its 13th-16th century church is a listed monument. Caix is situated on the D28 road, some 20 miles southeast of Amiens.