It is the youngest volcano in Greece and still activated. The volcano is 160.000 years old and the most recent eruption was in 1888. A great depression, Rammos and Lakki, are located just east of the center of the island. The west rim of this depression is formed by St. Elias, the highest point on the island. St. John mountain is on the east side.The largest crater in the valley is named Stefanos. The crater is ellipsoidal in shape and its longest axe is 330 meters in length and its shortest is 260 meters. Its walls culminate at 30 meters while it is estimated to be 3.000 to 4.000 years old.