Belgium generally is a low-lying country, with a broad coastal plain extending in a southeasterly direction from the North Sea and the Netherlands and rising gradually into the Ardennes hills and forests of the southeast, where a maximum elevation of 2,277 feet (694 metres) is reached at Botrange.
The main physical regions are the Ardennes and the Ardennes foothills; Côtes Lorraines (Belgian Lorraine), the intrusion of the Paris Basin in the south; and the Anglo-Belgian Basin in the north, comprising the Central Plateaus, the plain of Flanders, and the Kempenland (French: Campine).
The Ardennes region is part of the Hercynian orogenic belt of mountain ranges, which reaches from western Ireland into Germany and was formed roughly 300 to 400 million years ago, during the Paleozoic Era. The Ardennes is a plateau cut deeply by the Meuse River and its tributaries. Its higher points contain peat bogs and have poor drainage; these uplands are unsuitable as cropland.
A large depression, known east of the Meuse River as the Famenne and west of it as the Fagne, separates the Ardennes from the geologically and topographically complex foothills to the north. The principal feature of the area is the Condroz, a plateau more than 1,100 feet (335 metres) in elevation comprising a succession of valleys hollowed out of the limestone between sandstone crests. Its northern boundary is the Sambre-Meuse valley, which traverses Belgium from south-southwest to northeast.
Situated south of the Ardennes and cut off from the rest of the country, Côtes Lorraines is a series of hills with north-facing scarps. About half of it remains wooded; in the south lies a small region of iron ore deposits.
A region of sand and clay soils lying between 150 and 650 feet (45 and 200 metres) in elevation, the Central Plateaus cover northern Hainaut, Walloon Brabant, southern Flemish Brabant, and the Hesbaye plateau region of Liège. The area is dissected by the Dender, Senne, Dijle, and other rivers that enter the Schelde (Escaut) River; it is bounded to the east by the Herve Plateau. The Brussels region lies within the Central Plateaus.
Bordering the North Sea from France to the Schelde is the low-lying plain of Flanders, which has two main sections. Maritime Flanders, extending inland for about 5 to 10 miles (8 to 16 km), is a region of newly formed and reclaimed land (polders) protected by a line of dunes and dikes and having largely clay soils. Interior Flanders comprises most of East and West Flanders and has sand-silt or sand soils. At an elevation of about 80 to 300 feet (25 to 90 metres), it is drained by the Leie, Schelde, and Dender rivers flowing northeastward to the Schelde estuary. Several shipping canals interlace the landscape and connect the river systems. Lying between about 160 and 330 feet (50 and 100 metres) in elevation, the Kempenland contains pastureland and is the site of a number of industrial enterprises; it forms an irregular watershed of plateau and plain between the extensive Schelde and Meuse drainage systems.