It is really a great visualisation.
There is something way off in West Poland though.
I wonder where does the data come from. I just don’t think that in “Nowe Warpno” which is a village at the north-west of Poland at the border to Germany has population density higher than Berlin, or Moscow, while Stettin (Szczecin) - the biggest city in the Region - has almost nothing. There is really something strange going on - would be interesting to find it out…