If you are familar with the Basilica of St. Peter in Rome, this cathedral in St. Petersburg will look rather familiar:

For comparison, here is an old depiction of St. Peter’s in Rome:

Though they are not identical, the similarities are obvious.
The reason for this is that Tsar Paul I of Russia (1754-1801) once visited Rome as Tsarevich in 1782 and was mightily impressed by the basilica of St. Peter there. He wanted to create something similar in Russia. The architect Andrei Voronikhin was chosen to carry out the project in 1800, but Tsar Paul was assassinated in 1801 so never saw the completion of the cathedral in 1811, which was dedicated to the “Kazan” icon.
The new St. Peter’s-like cathedral was built on the site of the former church dedicated to the Nativity of the Most Holy Mother of God, which was the court church of the House of Romanov, the ruling dynasty.
The old Nativity church had been the repository of a famous copy of the “Kazan” icon of Mary — larger than the original — that had belonged to Paraskovia Feodorovna (born Saltykova), wife of Tsar Ivan V and sister-in-law to Tsar Peter I “the Great.” The new church was built to house this icon, thus its name.
Here is the Petersburg “Kazan” icon:

There is yet another icon in Saint Petersburg associated with Tsar Peter I. It had previously been owned by Natalia Kirillovna Naryshkina, second wife of Tsar Aleksey Mikhailovich (1629-1676), Peter’s mother. It is said to have been before this icon that Peter prayed for the blessing of his construction of the new capital, St. Petersburg. It is now kept in the Transfiguration Cathedral in St. Petersburg. It is also said to have been kept in Peter’s dining room, the first building constructed in what was to become the city.
While some investigators have attributed this icon to 1676 and the famous Armory painter Simon Ushakov, it differs considerably from his usual style, as we can see if we look at this icon more securely attributed to Ushakov, which gives a far less realistic depiction:
Given that both the “Kazan” and “Not Made by Hands” icons once owned by Tsar Peter I were very famous in St. Petersburg, many copies were made of them in that area in the latter part of the 19th century, often preserving a painted, rich golden appearance and painted jewels in imitation of the original riza (metal icon cover), which had since been changed.

Often these two icons — the Petersburg “Kazan” icon and the Petersburg “Image Not Made by Hands” icon were bought as a pair. Both of Peter’s icons were popularly believed to be “miracle-working,” but as you know, that is a common belief with many icons in Eastern Orthodoxy, so use your sense of reason.
You may recall that Peter I was the fellow who ended the Russian Patriarchate and put in its place the “Holy Governing Synod” which kept the authority in the Russian Orthodox Church securely under Peter’s thumb, just as the recreated Patriarchate today serves the will of Vladimir Putin.