This is the 516th most frequent Japanese word.
盛岡
Morioka: A city in Iwate Prefecture, Japan.
In this sentence, '盛岡' is used as a proper noun representing the name of a city located in Japan.
盛岡は美しい街です。
Morioka is a beautiful city.
In this context, '盛岡' acts as an attributive modifier, describing a type of cold noodles that are associated with or originated from Morioka.
盛岡冷麺はこの地域の特産品です。
Morioka cold noodles are a local speciality of this region.
Here, '盛岡' is combined with '市' (city) to specifically denote it as a municipality in Japan's Tōhoku region.