The Ardennes region is a large, elevated region, primarily forest. The boundaries of the Ardennes are not fast and firm; other regions such as the Belgian Lorraine may or may not be considered subsumed by the Ardennes. Generally, the Ardennes covers the southeastern portion of Belgium, stretching into the Oesling region of Luxembourg and the Eifel region of Germany. In Belgium, the Ardennes region is less developed than the rest of the country, due to the uncooperative topology of the terrain. Tourism is a mainstay of the economy.
One of the bloodiest battles of World War II, the Battle of the Bulge, was fought in the Ardennes, and is also known as the German Ardennes Offensive.