While walking along the bank from which the above photo was captured, I was under the impression that I had not yet reached Lake Mälaren but I am not so convinced now. That is why I gave it the title that you see here. There was a time when both Lake Mälaren and the Baltic Sea were linked but the most recent post-glacial rebound raised the height of the land such both were cut off from each other. Even today, there is a drop down to where the channel once would have been and a 5.2 km long canal has been constructed so modern day shipping can travel there. Because the height differences are not that much, only one lock is needed (the present one dates from 1924 and an earlier smaller one was built in 1819) and it allows large ships to use the cutting too. Evidence of that was provided during my walk by the passage of an huge container ship towards the lake. It is for this reason that road bridges over the canal raise and lower much like London's Tower Bridge.