Etymology and distribution of 井岡.

Ioka 【井岡】^{レベル5
About 3,300}  The Japanese surnames etymology dictionary.

Kyouto-fu . Terrain . A variant of 井笹 . Kyouto-fu Kyoutango-shi Yaizawa Town Yoshizawa has distribution.

Inooka 【井岡】^{レベル5
About 3,300}  The Japanese surnames etymology dictionary.

Gunma-ken , Fukuoka-ken , Ooita-ken .

① Gunma-ken Maebashi-shi Taki Kubo town is based. Gunma-ken Maebashi-shi It was in Otomi-cho during the Edo period. Tell them that they are groundbreaking in the same place. Gunma-ken Takasaki-shi Yoshii Town Yoshii was in the Edo period in the clan sister Yoshii of the Clan Office.

② Fukuoka-ken Chikujou-gun Chikujou-machi Origin of Iwamaru. A place name with a record since the Edo period.

③ Ooita-ken Nakatsu-shi Originated from Iwa-maru of Imazu's underwear.