Although in some countries the utilization of geothermal energy has a long history, in Turkey intensive research and exploration activities and evaluation of this potential source have been emphasized only after the establishment of the Geothermal Code, which was issued by the Turkish Assembly in June 2007. The geotectonic position of Turkey between the African-Arabian and Eurasian continents, and within the Alpine orogenic belt, has given rise to tectonic activity resulting in folding and faulting during several geological periods, and is still shown by the active tectonic zones (Canik and Baksan, 1983; Koçyig˘it et al., 2001, Kurtman, 1977; S¸engör, 1980; S¸engör and Kidd, 1979; S¸engör and Yilmaz, 1981). Several volcanoes, active in historic times, such as Kula, Erciyes-Hasandag˘, Nemrut, Süphan, Tendürek, and Ag˘rı Mountains are known (S¸arog˘lu et al., 1980), and these together with the tectonically active belts have given rise to the many hot-water springs that occur throughout Turkey (Fig. 9.1). It is possible to consider four main geothermal provinces, namely, the western Anatolia horst-graben system, the Northern Anatolia Fault Zone (NAF), and the areas affected by Upper Tertiary recent volcanic activity localized mainly in central and eastern Anatolia. Eastern Anatolian contractional province is characterized by E-W trending folds, manifestation of the N-S shortening, and a widespread volcanism with several young volcanoes emitting gasses and aligned in NE-SW direction. The important geothermal fields of the region are concentrated around these young volcanoes (Ag˘rı, Van, Mus¸, Bitlis, and Bingöl).