Here’s a link to a Google map that shows the precise location:

https://goo.gl/maps/ofuACyUQkBm

http://www.japantoday.com/category/travel/view/one-of-japans-stunning-secret-destinations-the-road-to-laputa-in-kumamoto

For more pictures, etc. see

http://en.rocketnews24.com/2015/12/06/we-visit-one-of-japans-stunning-secret-destinations-the-road-to-laputa-in-kumamoto/