Franconia's flora is dominated by deciduous and coniferous forests. Natural forests in Franconia occur mainly in the ranges of the Spessart, Franconian Forest, Odenwald and Steigerwald. The Nuremberg Reichswald is another great forest, located within the metropolitan region of Nuremberg. Other large areas of forest in the region are the Mönchswald, the Reichsforst in the Fichtel Mountains and the Selb Forest. In the river valleys along the Main and Tauber, the countryside was developed for viticulture. In Spessart there are great oak forests. Also widespread are calcareous grasslands, extensively used pastures on very oligotrophic, poor sites. In particular, the southern Franconian Jura, with the Altmühl Valley, is characterized by poor grassland of this type. Many of these places have been designated as a protected areas.