This is the 7276th most frequent Japanese word.
中津
"中津" (Nakatsu) is a proper noun referring to a city in Oita Prefecture, Japan, or can mean "middle harbor" depending on context.
Here, '中津' is used as a proper noun referring to a geographical location.
中津は福岡県の市です。
Nakatsu is a city in Fukuoka Prefecture.
In this sentence, '中津' again refers to the city, now as a destination within the narration.
旅行で中津に立ち寄りました。
I stopped by Nakatsu during my trip.
'中津' here specifies the location related to the castle, illustrating a connection to a landmark in Nakatsu.