Flanders
Flanders shares its borders with Wallonia in the south, Brussels being an enclave within the Flemish Region. The rest of the border is shared with the Netherlands (Zeelandic Flanders in Zeeland, North Brabant and Limburg) in the north and east, and with France (French Flanders in Hauts-de-France) and the North Sea in the west. Voeren is an exclave of Flanders between Wallonia and the Netherlands, while Baarle-Hertog in Flanders forms a complicated series of enclaves and exclaves with Baarle-Nassau in the Netherlands. Germany, although bordering Wallonia and close to Voeren in Limburg, does not share a border with Flanders. The German-speaking Community of Belgium, also close to Voeren, does not border Flanders either. (The commune of Plombières, majority French speaking, lies between them.)
Flanders
Flanders has two main geographical regions: the coastal Yser basin plain in the north-west and a central plain. The first consists mainly of sand dunes and clayey alluvial soils in the polders. Polders are areas of land, close to or below sea level that have been reclaimed from the sea, from which they are protected by dikes or, a little further inland, by fields that have been drained with canals. With similar soils along the lowermost Scheldt basin starts the central plain, a smooth, slowly rising fertile area irrigated by many waterways that reaches an average height of about five metres (16.4 ft) above sea level with wide valleys of its rivers upstream as well as the Campine region to the east having sandy soils at altitudes around thirty metres. Near its southern edges close to Wallonia one can find slightly rougher land richer of calcium with low hills reaching up to and small valleys, and at the eastern border with the Netherlands, in the Meuse basin, there are marl caves ("mergelgrotten"). Its exclave around Voeren between the Dutch border and the Walloon province of Liège attains a maximum altitude of above sea level.