The Olvios accented form Ólvios is a river that flows in western Korinthia in the northern Peloponnese

Peloponnese

The Peloponnese, Peloponnesos or Peloponnesus , is a large peninsula , located in a region of southern Greece, forming the part of the country south of the Gulf of Corinth...

 in Greece

Greece

Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

. The river empties only in a plain that once existed with swamps now containing farmlands. It is approximately 30 km long.

Geography

The river begins in the Mavros Mountains between Feneos

Feneos

Feneos is a village and a former municipality in Corinthia, Peloponnese, Greece. Since the 2011 local government reform it is part of the municipality Sikyona, of which it is a municipal unit. Its population was 2,359 as of 2001. The seat of the municipality was in Goura.In ancient times the area...

 and Derveni

Derveni, Corinthia

Derveni is a coastal town in prefecture of Corinthia in the Peloponnesus, Greece. It is the seat of the municipality Evrostini. It is linked by the old, mostly coastal, national road and a new, thought secondary, highway to mainland Greece and the Western Peloponnese.Its population stands at 1514...

 and flows along its valley between the Chelmos (Aroania) and Kyllini (Ziria)

Mount Kyllini

Mount Kyllini or Mount Cyllene , is a mountain on the Peloponnesus peninsula in Greece, famous for its association with the god Hermes. It rises to above sea level, making it the second highest point on the peninsula. It is located near the border between the historic regions of Arcadia and...

 mountains. The river empties into the Feneos Fields northwest of the Oligyrtos

Oligyrtos

Oligyrtos is a mountain located at the junction of the Arcadia, Corinthia and Argolis prefectures in the northeastern Peloponnese in Greece. The mountain diagonally stretches from southwest to northeast, with about 35 km length and 15 to 20 km breadth. The highest point is Skipiza at...

 mountains

Tributaries

The river has a few tributaries including the Doxa stream flowing west from Chelmos and flows via Lake Doxa

Lake Doxa

Lake Doxa is an artificial lake or reservoir at an elevation of 900 m. Located in west Feneos in Corinthia only 2 km east of the Achaia and Arcadia prefectural boundaries. Construction was completed in the late 1990s and occurred on the Doxa stream and a branch which flows in the area and...

 which a tributary of a smaller stream was located.

Places along the river

The Neda flows along the villages and towns of Karia, Ano (Upper) and Kato (Upper) Tarsos, Steno, Feneos, Messino, Mosia, Amygdalia, Achladies and Mati.