The westwall streches from south at Rheinfelden to the north at Kleve. It is said, that about 18.000 objects were build.
The first pre Westwall fortification were weak: The were the "Sperrstellen" in the Black Forest and the Ettlinger Riegel followed by the Pionierprogramm at the beginning of 1938 with about 430 bunkers of building strength "C" (0,60m) and "D" (0,30m).
At the end of 1938 the Limesbauprogramm was started. The buldings had 1,5m strong walls and ceilings (strength "B") of reinforced concrete. There were 11888 bulidungs planed. Some strategic positions were havy fortified with "B-Werke". First in strengh "A1" (2,50m) later in "A" (3,50m).
At the same time the Luftwaffe started bulding the "Luftverteidigungszone West" short "LVZ-West" with fotificated Flak positions in the back of the Westwall.
In 1939 the Aachen-Saar-Programm was started, now using strength "B neu" with 2m strong walls and ceilings. Followed by the Orscholzriegel and then Geldernstellung until 1940.
After D-Day there were many attempts to reactivate the Westwall, but many parts were missing, as apropiate weapons. At some positions new bunkers and Ringstände werde build to reinforce the positions.