It's a Russian enclave, but I don't know what it's called without looking it up. I'll be the first to say "Oooooh right" when someone does post the name.
Akshually it's a Russian exclave. That means it's disconnected from the main part of Russia. An enclave is like Vatican city which is totally surrounded by Italy. 🤓🤓
So, pre WWII that was more-or-less East Prussia. Does anybody know how Russian it is these days, in terms of language and culture? Is there any remaining hint of Prussianness vs Russianness? I would think that having no land route connecting it to the rest of Moscow might result in it having its own identity. But, I don't know enough about its history to know if any of the people there feel a connection to the pre-WWII identity.
OTOH, sometimes you get the opposite effect, like people in the Falkland Islands feeling even stronger connections to Britain than a lot of the people actually living in the British Isles.
Also, since it's the home of the Black Sea fleet, I imagine that means a lot of Russians in the navy moving there, which would tend to exert a strong Russian cultural influence on the area.