Zao Onsen sits on the Yamagata side of the Zao mountain range and is known for strongly acidic, milky-white sulfur baths as well as for the Okama crater lake, a volcanic caldera lake whose color shifts between shades of green and blue depending on light and mineral conditions. In winter the area is also known for its frost-covered conifers, but as a day trip in other seasons it's really a combination of a soak and a short hike or ropeway ride to the crater viewpoint. It's the furthest and most involved of these trips given the train-plus-bus connection.
| Distance | 90 km from Sendai |
|---|---|
| Travel time | 80–100 minutes (Shinkansen to Yamagata 30 min + bus to Zao 50 min) |
| Getting there | Shinkansen Tsubasa from Sendai to Yamagata (30 min, ¥2,780 / ~$18.40); then Yamakobus bus to Zao Onsen (50 min, ¥1,050 / ~$6.90). Okama road open June–October; Zao Echo Line bus from Zao Onsen (confirm at zaoonsen.or.jp). |
| Address | Zao Onsen, Yamagata 990-2301 (Yamagata Prefecture — 90 km from Sendai) |
How to get there
- Shinkansen + bus (most common); rental car (most flexible)
Location
Zao Onsen, Yamagata 990-2301 (Yamagata Prefecture — 90 km from Sendai)
38.1455, 140.4526 View on map
Highlights
- Okama Crater Lake - the volcanic caldera lake and viewpoint, reachable by road or hiking trail depending on the season
- Zao Onsen sulfur baths - distinctively cloudy, acidic hot spring water rated among the more potent in the region
- Zao Ropeway - a cable car running up toward the mountain's upper slopes, used for both the crater access and general views
- Zao Onsen outdoor bath (rotenburo) - an open-air bathing area built directly into the hillside above the town