Masurian Canal

The Masurian Canal (, , ) is an unfinished 50.4 km long canal connecting the Lava River in Kaliningrad Oblast of Russia (a tributary of the Pregolya) and Lake Mamry, one of the Masurian Lakes in Poland. 
The present-day Polish-Russian border cuts through the canal, with the southern section, about 20 km long, located in Poland, and the remainder in Russia. There are ten locks on the canal, five in each country, designed to handle boats up to wide, long, with a draught of .
The canal's purpose was to spur the economic development of East Prussia. Construction began in 1911 but was interrupted by World War I, was resumed in the 1920s – since Russian trade ceased after the October Revolution – and again in the 1930s. The project was finally terminated by World War II, with no attempt to finish the canal afterwards.