According to the Japan Meteorological Agency, there are 108 active volcanoes in Japan. Here is a list of popular spots to see volcanoes. Please be aware of volcanic warnings and restrictions when you visit any volcanic areas in Japan.
The Asozan volcano (Mt. Aso) is situated in the center of the Aso Kujuu National Park in Kumamoto and Oita prefectures.
Mt. Nakadake Crater
Location: Aso-city, Kumamoto prefecture
Access: By bus from JR Aso Station to Asozan-nishi Station. Take the Mt. Aso Ropeway to the crater.
Mt. Aso Information by the Aso Volcano Disaster Prevention Council
Sakurajima is a peninsula connected to the Osumi peninsula in Kagoshima and consists of active volcanoes.
Access: Takes about 15 minutes by the Sakurajima Ferry from the Kagoshima Port to the Sakurajima Port.
Sakurajima Information by Kagoshima Prefectural Visitors Bureau
Mount Kusatsu-Shirane is an active volcano located in Kusatsu-town, Gunma prefecture. Kusatsu is a well-known Japanese hot springs and snow resort.
Yugama (Shirane Volcano Crater Lake)
Access: It takes 35 minutes by bus from Kusatsu Onsen to Shiranekazan (Shirane Rest House). 20-minute walk from the Shirane Rest House to Yugama.
Mt. Shirane Information Page by Kusatsu Onsen Tourism Association
Mt Usu is located about 30 miles southwest of Sapporo-city near Lake Toya in Hokkaido
Mt. Usu Crater Observation Deck
Access: Take the Usuzan Gondola from the Sanroku Station to the Sancho Station.
Unzan Gondola Website
Mt. Asaka is located on the border between Nagano and Gunma prefectures in Karuzawa-town, Miyota-town, and Tsumagoi-town.
Location: 1053 Kanbara Tsubagoi-mura Agatsumagun, Gunma
Access: 30 minutes by bus from Shinano Railway Nakakaruizawa Station or 40 minutes by bus from JR Nagano Shinkansen Karuizawa Station or 25 minutes by bus from JR Agatsuma Line Manza Kazawaguchi Station