# Travel Destinations | Japan Voyage Travel

- [Oka Castle Ruins](https://travel.japanvoyage.jp/travel_destinations/oka-castle-ruins): Oita, Castle. Dramatic hilltop castle ruins that inspired the beloved song Kojo no Tsuki, offering spectacular views and atmospheric stone walls.

---
Source: [Travel Destinations | Japan Voyage Travel](https://travel.japanvoyage.jp/travel_destinations?destination_type=castle&prefecture_id=44)
Last updated: 2026-11-13