Simon, Elja also thought it resembled the dome of the St. Peter. I have to ask Tatyana (pp11364) which cathedral this is. When I know its name I can find more details on its history. Perhaps there has been Roman influences!
Haha, I can be blind with open eyes, yes Elja already mentioned it before. My thought now is - the term czar originates in the name Caesar, so I can imagine the roman culture also influenced architecture.
Senna,it is the Kazan Cathedral.It was founded 1801-1811.The architect is A.N.Voronikhin.This cathedral is situated in the centre of the city along the main street-Nevsky Prospect.