Karasawa Cirque, Glacial cirque in the Northern Japanese Alps, Matsumoto, Japan

Karasawa Cirque is a crescent-shaped glacial basin about 2 km across in the Northern Japanese Alps, with its floor at 2,300 m and a 900 m rise to the rim at Mount Okuhatakadake (3,190 m). The south side is closed by the吊尾根 ridge linking Okuhatakadake and Maehotakadake, while the east holds the peaks of Maehotakadake's north ridge, ending at the 1,000 m-high cliff of Byōbu-iwa. Snowfields persist into summer, and the cirque walls show dark rock ribs above the snow.

The cirque formed through two distinct glacier phases identified by geographer Tomoya Iozawa: the Yokoo Glacier around 60,000 years ago and the Karasawa Glacier around 20,000 years ago. This research revealed how the mountain landscape changed across different climate periods.

The cirque's name, Karasawa, means "dry valley", yet snow persists here into summer, and the basin is a base for summer skiing as well as for climbing Mount Hotakadake. In autumn the slopes are known for sandan kōyō, a three-tiered display in which snow, rock and turning trees appear together. Two huts, Karasawa Hütte and Karasawa Hut, stand on the cirque floor.

Access comes from Kamikochi Bus Terminal along a hiking route covering roughly 30 kilometers, normally taking two days. Along the way, hikers pass several established stations like Myojinkan and Tokusawa-en where they can find lodging and supplies.

Meltwater from the cirque feeds the Azusa River, which merges with the Sai River and eventually becomes Japan's longest waterway. This water connection ties the high mountain basin to the country's broader river system.