Oka Castle
Oka Castle is the name of the following castles in Japan:
- Oka (Chikuzen) Castle in Okagaki, Fukuoka Prefecture
- Oka (Shinano) Castle in Ueda, Nagano Prefecture
- Oka (Yamato) Castle in Kashiba, Nara Prefecture
- Oka (Bungo) Castle in Taketa, Oita Prefecture
- Oka (Musashi) Castle in Asaka, Saitama Prefecture
- Oka Castle (Shimotsuke) in Yasaka, Tochigi Prefecture
- Oka (Inaba) Castle in Tottori Prefecture
