The view from the castle is nice, and it's very easy to get to (especially with the car park right at the base of the castle).
The interior is sparse, just concrete walls, but it has some interesting pieces about the Christian history from the region
Peaceful and picturesque park with lots of sculptures by Seibo Kitamura, who also sculpted the Nagasaki Peace Park sculpture Prayer Monument for Peace. Visited last week November and Gingko tree leaves were a bright yellow, while the maple leave were turning a bright red. Quite magnificent!