I'd like to ask if it is correct to say "I'm interested in architecture so the most I'd like to visit places such as Westminster Abbey and the Tower Bridge." I mean if the most goes before the subject and the predicate, is it wrong word order?
The word order in your original sentence is wrong. A more idiomatic way to phrase it is
I'm interested in architecture, so the places I'd most like to visit are...
This emphasizes the places that you want to visit more than any others - of all places, these are the ones you most want to visit.
Another way to phrase it would be
I'm interested in architecture, so I'd most like to visit places such as...
This changes the focus of the sentence a little - of all things, what you would most like is visiting these places.