I found the exact location of the scene at the preview of episode 10

fatimagochi:

Not sure if anyone else have found it, but I finally know where exactly the scene is going to take place.

The scene is at the stairs at the front door of the
Catedral de la Santa Cruz y Santa Eulalia de Barcelona. I got to google and searched for famous Barcelona places and this was the fifth entry, I used maps street view and voila!

Here is the comparison of the fence at Viktor’s part

and the real thing:

And then we have Yuuri’s part, and what many people have missed is the door at the back of Yuuri and the design:

and here is the real one:

So yeah, we found the location. I think someone else already pointed this place out, but the pictures provided were not of the exact location, so here is my little contribution

Also, this last picture doesn’t belong to me, just found it at google because I wanted a night shoot of the place with the fence closed.