摘要：The phenomenon Duvalo in the vicinity of Ohrid has always been subject of interest among scientist and the general public. All geological manifestations occurring at this locality are a constant challenge for anyone attempting to research or explain them. So far, some researchers consider this structure is representing a solfatara while others consider it a mofette or fumarole. There are even articles in newspapers stating it represents the only “active volcano” on the Balkan Peninsula.With the aim to clarify some important facts for the location and eliminate the multitude of arbitrary and unprofessional interpretations and information, within the frame of this article are presented results of analysis of all the available geological and geomorphological existing documentation for the phenomenon. Based on such detailed analysis with taking into consideration the character of its activity, the composition and the measured temperature of the gasses, geomorphological futures etc., the occurrence is classified as a “dry moffete”. The presence of the H2S gas in mofettes appearing on non-magmatic regions is very unusual and requires further research. Therefore, at the end of the paper are presented the minimum required investigations which will help define the origin of gasses at the Duvalo occurrence.
