The Maginot Line was a line of concrete fortifications, tank obstacles, machine gun posts and other defences which France constructed along her borders with Germany and with Italy in the wake of World War I. Generally the Maginot Line refers to either the entire system or just the defences facing Germany while the Alpine Line is used for the Franco-Italian defences. The French believed the fortification would provide time for their army to mobilise in the event of attack and also compensate for numerical weakness. The success of static, defensive combat in World War I was a key influence on French thinking.
The line was built in a number of phases from 1930 by the STG (Section Technique du Génie) overseen by CORF (Commission d’Organization des Régions Fortifiées). The main construction was largely completed by 1935 at a cost of around 3 billion francs. The specification of the defenses was very high, with extensive and interconnected bunker complexes for thousands of men, there were 108 main forts (ouvrages) at 15 Kilometer intervals, smaller ouvrages and casements between with over 100 Kilometers of tunnels.
The fortifications did not extend through the Ardennes Forest (“impenetrable” and “impassable”) or along the border with Belgium because the countries had signed an alliance in 1920, by which the French army would operate in Belgium if the German forces invaded. When Belgium abrogated the treaty in 1936 and declared neutrality, the Maginot Line was quickly extended along the Franco-Belgian border, but not to the standard of the rest of the Line. There was a final flurry of construction in 1939-40 with general improvements all along the Line. The final Line was strongest around the industrial regions of Metz, Lauter and Alsace, while other areas were in comparison only weakly guarded.
http://www.battle-fleet.com/pw/his/Maginot%20Line%20WW2.htm
The Germans went right through the Ardennes forest, and took france over in a matter of days. I understand that the French were outflanked badly, but how can you lose your ENTIRE country and army in about a week? It just doesnt seem possible, any help?