This is the 8879th most frequent Korean word.
강북구가
The term "강북구가" seems to be a typo or unclear. If you meant "강북구," it refers to "Gangbuk-gu," a district in Seoul, South Korea.
Here, '강북구가' is the subject of the sentence, marked by the subject particle '가', and refers to the district Gangbuk-gu.
나는 강북구가 아름답다고 생각해요.
I think Gangbuk-gu is beautiful.
In this sentence, '강북구가' specifies the location where the new park exists.
강북구가 새로 지어진 공원이 있어요.
There is a newly built park in Gangbuk-gu.
'강북구가' identifies Gangbuk-gu and provides a descriptor about its geographical classification.