Mt. Inasa Observatory 稲佐山展望台
I recommend going to Nagasaki as well. In Nagasaki there is the Mt. Inasa Observatory that can be reached by a cable car. The view is fantastic and perfect for when the night is a little warm.
The part that I enjoyed the most is the fact that the city was very close to nature.
There were mountains and bodies of water everywhere I looked.
I even found this heart shaped stone. Be sure to try to find it when you visit!