So I saw Kernals12's thread about projects we would like to see and it got me thinking about something: we rarely address that which we might have refrained from building. For this reason, I wanted to start a thread about about buildings and projects that we can look back on and wonder if we should have built them differently or perhaps, not built them at all.
Much of this is subjective and it's not as interesting, by and large, as speculating about what we could have built but the fact of the matter is, of the many things we've constructed mistakes have been made.
BTW, this isn't really meant to be about stuff with fundamental safety flaws like collapsed bridges, rather just poor design considerations.