The Danube-Black Sea Canal is a man-made ship canal similar to the Panama Canal.The canal links the river Danube to the Black Sea.The main purpose of the canal is to shorten the distance between the river Danube and the Black Sea by about 400 km.It also circumvents the river Danube Delta which is hard to navigate and is unsuitable for shipping.The main branch of the canal is about 64 km long and was built between 1976-1984 while the secondary north branch of the canal is about 31 km long and was built during 1983-1987.The site of the canal was previously a site of Communist forced-labor camps for political prisoners especially during the 1950s Stalinist era.Plans for the building of the canal existed since the 19th century but actual work on the canal didn't start until 1949 when the Communist regime decided to use political prisoners from nearby Soviet-style gulags to dig the canal.Work on the canal was suspended in 1955 and re-started in 1976.The canal has a width of 90 m (300 ft) and a depth of 7 m (23 ft).It has four locks.In its final phase the canal took nine years to build.Almost 381,000,000 cubic meters of earth were dug and over 5,000,000 cubic meters of concrete were poured into the support walls and locks. (source: Wikipedia)