the western part of the Rhenish Slate Mountains, north of the Mosel River, in the Federal Republic of Germany. The Ei-fel is approximately 90 km long and rises to an elevation of 747 m in the Hohe Acht. It consists primarily of slates overlain in places by basalts and tuffs. There is a plateau characterized by volcanic forms such as maars and the domes of extinct volcanoes. There are numerous lakes. Peat bogs and heaths are encountered, and coniferous and mixed forests are found in the northwest. The Su-deifel and Nordeifel natural parks are in the Eifel.