Kurobe Dam — Japan's Tallest Dam & Thundering Spillway

**Water release timing:** The spillway operates late June to mid-October (exact dates vary yearly), 10:00–16:00 daily. Peak flow (10+ tons/second) occurs early July to late August. For rainbow photography, visit on sunny days 11:00–14:00 when sun angle creates rainbows in the mist. The Shintenbo Observation Deck offers the best rainbow view angle. Early morning and late afternoon have weaker rainbows due to sun position. **Multiple viewpoints strategy:** Walk the dam crest (492m, 15 minutes, spectacular 186m drop on both sides) for scale. Then take the stairs to Shintenbo Observation Deck (220 steps up, 15 minutes) for elevated panoramas — this is the classic postcard angle showing the full dam arc and water release. Finally, descend to Garbe platform (base level, 5-minute walk) to feel the spray and thundering roar up close. Allocate 1.5 hours for all viewpoints. **Kurobe Lake boat:** From June to early November, a sightseeing boat (Garve, ガルベ) operates on Kurobe Lake, offering 30-minute cruises (¥1,100) across the emerald reservoir with views of surrounding peaks. The boat departs from Kurobe Dam station — combine with dam visit. The lake's emerald color comes from glacial silt suspended in meltwater. Boats depart hourly; no reservation needed but weekends can sell out. **Winter access note:** The Alpine Route closes December to mid-April, cutting off Toyama-side access. Ogizawa Station (Nagano side) offers limited access to the dam via Kansai Electric Railway year-round, but the dam area is snow-covered and spillway is inactive. Visit is best April–November when all facilities operate and mountain scenery is accessible.