The document discusses the Odra river which runs through Poland and connects several major cities including Szczecin, Frankfurt, Zielona Góra, Wroclaw, and Opole. It notes the river's total length of 854 km and economic length of 742 km. The summary highlights that the river historically served as an important economic link between these cities but that this connection is now forgotten. It suggests activating the river again through improvements like water infrastructure and water tram connections to take advantage of attractions along the river and better connect the cities.