群马县

Gunma is a landlocked prefecture northwest of Tokyo, where the Kanto plain crumples into volcanoes and hot spring valleys. It is Japan's onsen heartland; the prefecture's spa towns have drawn bathers from the capital for centuries, and its mountains fill with skiers and hikers by season.

Kusatsu Onsen is the star, its steaming yubatake hot water field sitting in the middle of town while bathhouse staff cool the water by paddling it in a chanted ritual. Ikaho climbs a long stone stairway lined with inns, and the UNESCO-listed Tomioka Silk Mill preserves the 1872 factory that launched Japan's modern silk industry.

Minakami adds rafting and canyoning in the warm months and small ski hills in winter, with Mount Tanigawa's ropeway running most of the year. Eat hand-rolled mizusawa udon near Ikaho. Trains and buses reach the main spa towns from Tokyo, and an overnight in Kusatsu is the classic Gunma trip.