It's old buildings and culture. Shame it is going to have to be now blended as it allows immigrants and yes the EU can increase the speed of that happening. I'm sure I would've appreciated the other Countries culture, and architecture as well if I had visited. Now all I have are my photographs from when I was there.
I think you passed the point of no return and now have to accept being a blended country, and so have the other countries there.
Also, your need of a global control, laws and trade/economy, eventually is going to make individual countries and laws obsolete. This will not happen in my Lifetime, I hope. The Federation is coming. Your actions have consequences, and you liberals/socialists tend to not recognize them.