Kumamoto Castle Originally built by Kato Kiyomasa in 1607 after seven years of construction, the Kumamoto Castle today is one of the three most famous fortress-castles in the country. Kiyomasa hilltop castle is a brilliant architectural statement, exhibiting highly advanced engineering, superb masonry, and a mastery of flood control and defense. The un-scalable J-shaped stone walls and wooden overhangs, designed to repel the ninja (secret assassins of feudal Japan), made the castle virtually impregnable.
Mt.ASO Aso is the site of largest volcano caldera in the world. The caldera is an enormous bowl-like depression, 11 miles wide - 15 miles long (18 km x 24 km) and amazingly, it is lined with gently rolling, broad green grassy plains and ponds. Grazing cows and horses and whole little towns and villages of over 80,000 people reside in the caldera.