The acropolis of Osdina and Raveni stand as guards at the beginning and the end of the river. The estuary, which is defined by the triangle Igoumenitsa - Raghio - Saghiada, was created during its long-lasting course at the river mouth by the Ionian Sea. The extremely rare curlew has been observed here, during its long journey between Central Africa and Siberia. At the estuaries herons come to spend the winter. The number of Egrets, wintering in Kalama, is among the largest in E. Mediterranean.