The Onioshidashi Park (So, Onioshidashien) features a landscape of volcanic rocks that gives it an unique and rugged appearance. The park is shaped by volcanic sediment deposited here during the 1783 big eruption of Mount Asama. It is located just across the prefectural border in Gunma Prefecture, but popularly visited in combination with Karuizawa.

Besides presenting the opportunity to take a closer look at the volcanic rocks of various curious shapes, Onioshidashi Park also offers nice views looking over nearby towns and of Mount Asama on clear days. Located at the center of the park stand a temple dedicated to the Buddhist Goddess of Mercy Kannon.

A short distance from the park is the Asama Volcano Museum, where visitors can learn about the geography of volcanoes, as well as about plant and animal life on volcanic terrains. Visitors can also experience volcanic activity through a video presentation on large screens and by riding on a simulator.

Getting there and around

Seibu buses operate almost hourly between Karuizawa Station, Naka-Karuizawa Station and the Onioshidashi Park. The one way ride between Karuizawa Station and the park takes 35 minutes and costs 1230 yen.

How to get to and around Karuizawa

Hours and Fees

Onioshidashi Park


8:00 to 17:00 (entry until 16:30)


No closing days


650 yen

Asama Volcano Museum


8:30 to 17:00 (entry until 16:30)


Wednesdays and December through March


600 yen