What allowed the German army to travel through the difficult terrain of the Ardennes so easily in 1940?

The German army's ease of movement through the difficult terrain of the Ardennes in 1940 can be attributed to several factors. Firstly, their use of highly mobile and mechanized units, including tanks and motorized infantry, enabled rapid advances. Additionally, the element of surprise played a crucial role, as the Allies had anticipated a direct attack through Belgium and were unprepared for the German flanking maneuver. Lastly, effective planning and coordination within the German command allowed for efficient exploitation of the terrain, overcoming its challenges.