It was indeed early in the morning dear Midworlder! :)
This path was originally destined for horses: they had to pull a ship from one place to another... It is just wide enough for one person on a bike and you can follow this centuries old path over quite some distance!
If I remember it correctly you uploaded a picture of it some time ago, dear Hans! But it also maybe another one of those military sluices. You are the expert!!! :)))