Mt. Aso - the symbol of the “fire country” of Kumamoto. The massive caldera, formed by subsidence in the wake of an eruption, is one of the world’s largest, stretching some 18 km east to west, and 25 km north to south. Actually, “Mt. Aso” is often used not to refer to a single mountain, but rather as a collective term for the caldera and a group of volcanoes rising out of the caldera’s center, which also encompasses the mountains formed on the outer rim of the caldera. The five volcanoes formed within the caldera are Mt. Nekodake, Mt. Takadake, Mt. Nakadake, Mt. Eboshidake, and Mt. Kishimadake. These are collectively referred to as the “five Mt. Aso peaks.”

Of the five Mt. Aso peaks, Mt. Nakadake remains the most active. This is a popular tourist destination, offering up-close view of a massive crater spanning some 600 meters in diameter, 130 meters deep, with a circumference of 4 km. Here you can get a real sense of the earth inhaling and exhaling with the smell of sulfur enveloping the area, the molten rock exposed on the mountainside, and scenes of the dynamic crater bursting into life when expelling volcanic smoke. To get to the crater, you can opt to drive the Mt. Aso Park Road, or ride a tour shuttle bus departing from the Aso Sanjo Terminal (services may be suspended without notice due to inclement weather or the presence of volcanic gas). A one-way trip to the crater by bus takes about 5 minutes. Check the level of volcanic activity before heading out.