http://edition.cnn.com/2017/02/22/arts/japanese-abandoned-theme-park/index.html
It is interesting that CNN took up the theme park in my home prefecture.
Though the exact reason why it failed is not described on the article, the main reason is inauguration of Universal Studio Japan in Osaka, which deprived theme parks in Kansai of their customers.
So, you can find ruins of theme parks not only in Nara, but also the other prefectures in Kansai.
