Erymanthos (, Latin:
Erymanthus, also
Olonos (Ωλονός)) is a mountain range in the southern part of
Achaea and the northeastern part of
Elis. With an elevation of 2,224 meters, it is the fourth-tallest mountain in the
Peloponnese peninsula. The summit is located on the boundary of Achaea and Elis. Historically, Mount Erymanthos was part of northwestern
Arcadia, where it was the second-tallest mountain range. The northern portion belonged to the historic Achaea.