Oh wait - duh, it's a mosque now isn't it! Gold domes are an
  architectural style from the East. The Eastern Orthodox (Greek
  Orthodox, Russian Orthodox, etc) Christians were the first to
  use the gold and silver domes as far as I know (cupolas) and
  mosques that came later used the same architectural style as
  they started growing as a religion in the same area as the
  Eastern Orthodox. The fall of ...the Eastern Roman Empire
  (something we don't learn in school) was in 1463 or something
  like that, when Constaninople (now Istanbul) was taken over by
  the Turkish empire. But thankfully, some of the scholars had
  already moved to Italy before then and started up secret schools
  which taught folks in the West (which was still going through
  the Middle Ages - there were no middle ages in the East) --
  which brought knowledge of the Greek philosophers and ar... "