Situated at the curvature of the Carpathians, between Buzău and Braşov, the Muddy Volcanoes are larger (“Pâclele Mari”) or smaller (“Pâclele Mici”) craters in the yellow argillaceous soil of the area through which, under the pressure of subterraneous gases, cold muddy eruptions come to the surface. This black mud originates from rain water that penetrates the soil all the way down to the oil deposits. In time, mud has oozed out through the craters and made a 20 cm. thick layer on the soil. In the sunlight, the eruptions have a metallic aspect. The smell of oil and the stifled noise of the gas bubbles coming out to the surface have given rise to many a legend and superstition by means of which the locals have tried to explain away this geological phenomenon that is unique in Europe.