Happo-ike Pond

Happo-one's gondola and two chairlifts, together called the Happo Alpen Line, lift walkers 1,060 metres to the first cairn at 1,830 metres in under 40 minutes. From Happo-ike Sanso, the hut at the top, the trail to the pond takes about 90 minutes on the gentler left-hand route with its boardwalk. The right-hand route goes straight up the rocky ridge in about an hour. Allow an hour to come down.

The pond formed where snow shoved rubble into a hollow that now fills with meltwater and rain. Happo-one is serpentine rock, which lets alpine plants grow far lower than usual, and the operator counts 347 species on the ridge, some of them found nowhere else and named for Happo. Japanese serow and rock ptarmigan live up here as well. Above Kurobishi the ridge sits inside Chubu Sangaku National Park and is a Nagano prefectural natural monument, so keep to the path.

Pack rain gear and a warm layer, because weather on the ridge turns fast, and wear hiking boots or sturdy trainers you don't mind getting muddy. Karamatsu-dake (2,696 m) rises beyond the pond. Anyone heading on from Happo-ike must file a climbing plan first, online or at the gondola station or the hut.