When in the region of Drama, it is worth visiting the Aggitis cave (or Maaras), which is located NE of the capital. The cave is an elongated natural pipe which is almost the only draining path for the waters collected in the closed basin of Kato Nevrokopi. It is a river cave, the only one existing in Greece, and it was first explored by speleologists Yannis and Anna Petrocheilou of the Hellenic Speleological Society (H.S.S.) in 1952, who only observed 70 m of it. Later, in 1978, French and Greek speleologists explored the cave in a depth of 500 meters. Nowadays, 8.5 km have been explored, only 2.5 of which are accessible. Today the visitor can enter the cave from the artificial entrance that has been opened and walk for 500 m. Stalactites of various forms, sizes and colors decorate the cave. As for stalagmites, their number is very limited because of the continuous flow of the river. The “mill chamber” is very interesting: the visitor can admire an amazing technical accomplishment of the local popular mechanics dating back to the 19th century. A rotatable waterjet pushed the water to a channel, specially constructed for this purpose, which led the water in the plain in order to irrigate the tobacco crops of the region. It is worth mentioning that this first chamber of the cave offered shelter to persons living during the 4th millennium B.C. (Neolithic—Copper-stone Age) and according to the findings the chamber was continuously used until the Post-Byzantine era.