Södertälje Canal

The water level difference between Mälaren and the Baltic Sea is not large, on average 0.6 m (2 ft).

This is the main shipping route into the lake Mälaren.

In the Viking age the passage was navigable by boats, but the Post-glacial rebound made it unusable.

In the year 1819 a lock was finished, so boats could use the canal.

In 1924 a much larger lock (that remains in use today) was built and the canal was widened and deepened.