If sleeping within an active volcanic caldera sounds like fun, book a night or two in Aso. It's a unique experience that's worth the trip. Mt. Aso is one of the largest volcanic calderas in the world, measuring 15 miles (25 kilometers) from north to south, and contains towns—such as Aso—within it. The volcanic activity means there are some fun things to do in Aso, including viewing steaming pools, hiking through a lunar-like landscape, and whiling away hours in natural hot spring baths.
There are experiences to enjoy around Aso at any time of year. Spring (March–May) and fall (October–November) are the best seasons for hiking, as the weather is generally warm and dry. Summer can be humid and wet, so you might not get the best mountain views, but as Aso is at about 1,640 feet (500 meters) altitude, it’s cooler than low-lying Kumamoto. Winter is generally low season, and some attractions may be shut, but it’s a good time to soak in the hot springs.
Having your own vehicle is handy for fully exploring the Aso area, but it’s not entirely necessary. Travelers without a car can reach Aso from Kumamoto in about two hours: It’s on the JR Hohi line. (In contrast, this is about a 1.5-hour drive). Buses connect Aso town with various points of interest, including the Nakadake Crater and Kurokawa Onsen hot springs town.
When visiting a volcano as active as Mt. Aso, it’s important to be aware of any safety alerts. Mt. Aso erupts every few years, and the safety is constantly monitored—people live within the volcanic area, after all. No-entry zones are often established when volcanic activity is too high or local winds blow in the “wrong” direction. Don’t be surprised—or disappointed—if you can’t see the volcanic crater of Nakadake during your visit. Better safe than sorry.
