Aso Nakadake Crater

Mount Aso is Japan's most active volcano, featuring a massive caldera that stretches 24 kilometers from north to south, surrounded by the five peaks known as Aso Gogaku. The mountain range runs east-west with Mount Takadake, Mount Nekodake, Mount Nakadake, Mount Eboshidake, and Mount Kishimadake at its heart, creating a magnificent caldera measuring 24 km north-south and 18 km east-west. This natural wonder represents one of the world's largest volcanic calderas and has been shaping the landscape for over 90,000 years.

Nakadake Crater stands as the centerpiece of this volcanic complex and remains one of the few places globally where visitors can witness active volcanic activity up close. The crater measures 600 meters in diameter, 130 meters deep, with a circumference of 4 kilometers. Among seven craters in Nakadake, the first crater is currently active and accessible to visitors. When gas conditions permit, visitors can observe the emerald green crater lake at the bottom, filled with water heated to temperatures between 50-60°C.

The volcanic activity creates a constantly changing spectacle as the ground rumbles and volcanic steam rises from the crater. The crater lake was formed by the collection of rainwater and spring water in the crater bottom, making it a rare geological phenomenon. The surrounding area showcases the raw power of volcanic forces, with loose volcanic materials and dramatic landscapes that demonstrate the mountain's active nature.

Visitors experience the volcano through carefully managed viewing areas that provide safe access to witness this geological marvel. The proximity to active volcanic processes offers an educational opportunity to understand volcanic systems and their impact on the surrounding environment. The Aso Volcano Museum near Kusasenri provides additional context about the caldera's formation and volcanic activity.

Access begins with buses departing JR Aso Station every 1-2 hours for the Asosanjo Terminal, costing 1,000 yen one way, with stops at Kusasenri along the way. From Asosanjo Terminal, visitors take a shuttle bus to reach the crater for 700 yen one way, though current shuttle pricing shows 500 yen for adults and 250 yen for children. By car, the journey takes 1 hour and 10 minutes from Kumamoto IC via Route 57 and the Mt. Aso Summit Route. Access to the crater area is subject to volcanic activity levels and gas emissions, with restrictions implemented for visitor safety when conditions warrant.