This is the 3696th most frequent Chinese word.
莫斯科
Moscow.
Here, '莫斯科' is used as a proper noun referring to the city of Moscow.
莫斯科是俄罗斯的首都。
Moscow is the capital of Russia.
In this sentence, '莫斯科' is again a proper noun, acting as the object of the verb '去过' (visited).
我曾经去过莫斯科旅游。
I have traveled to Moscow for tourism.
In the example, '莫斯科' is used as part of the possessive construction '莫斯科的', indicating that the described style pertains to Moscow.