You might have never heard of the Curonian Spit before visiting Russia.com or travelling the Baltic Sea. Viewed from above, this curious, long and thin sand dune peninsula is a true marvel. It measures roughly 98 kilometres in length and it separates the Curonian Lagoon from the Baltic Sea. Interestingly, because the Spit starts at the Sambian Peninsula - which is in Russiaâ€™s Kaliningrad Oblast - and ends at the city of Klaipeda in Lithuania, the spit is both a part of Lithuania and Russia. The Russian portion of the spit measures some 46 kilometers in length. The Curonian Spit is 400 meters at its narrowest point and 3 800 meters at its widest point..