It comes from the heart of Erymanthos below the tops of the mountains. In the upstream, it rapidly flows through the spectacular deep gorge between Olonos (2221 m) and Prophet Elias (2124 m) retaining water permanently, even in summer. Great falls formed the bed of the river and the streams pouring from the steep side of Prophet Elias.
Under Alepochori the river landscape is becoming more moderate concerning the terrain and the banks are often covered by dense trees (Acer helbreichi), to contribute finally to Peiros river in the Industrial Areas of Patras near Agios Stephanos.