Aso Kusasenri and Crater Area

This is the route's most important weather-and-safety-sensitive section. The official disaster-prevention site publishes seasonal park-road hours and warns that access can change according to gas conditions, while the Aso City page highlights both the grassland scenery of Kusasenri and the need to keep away from grazing horses. For itinerary planning, treat the crater as a same-day bonus rather than a guaranteed stop; if restrictions tighten, keep the day focused on Kusasenri, viewpoints, the museum area, and a smoother arrival into the onsen stay.