About 80 percent of inland water transport in Poland is based on the Odra river. The remaining 20 percent works on the Wisla-Odra waterway, The lower Wisla river on the stretch from Plock to Gdansk and the Wloclawek water reservoir as well as partly on the upper part of Wisla river between Oswiecim and Krakow. The largest ship trafficking is performed between Szczecin and the inland Western European ports. There is not a great deal of transport between Szczecin and the ports situated down-stream near the Wisla. Inland connections are facilitated to the Russian port of Kaliningrad situated on the Zalew Wislany.