Okama Crater, also known as Goshiki-numa or the “Five-Color Marsh,” is a volcanic crater lake situated on Mount Zao. It is one of the most famous and picturesque attractions in the region. Mount Zao sits on the border between Yamagata and Miyagi Prefecture, with a maximum height of 1,841m. The crater is approximately 1,084 meters above sea level and has a diameter of around 300 meters.
What makes Okama Crater particularly remarkable is its ever-changing colors, which vary depending on the weather and time of year. The lake can exhibit colours of a deep green or more of a turquoise, while sometimes the water can be more gray, and even reddish-brown along the edges of the water. The colours result from the varying mineral content and algae present in the water, as well as varying levels of sunlight.
The surrounding landscape around Okama Crater is also visually stunning, with lush greenery, rocky slopes, and the nearby volcanic peaks of Mount Zao. Visitors can enjoy hiking trails and observation areas to appreciate the beauty of the crater from different angles.
The water of Okama crater is hazardous to life, and visitors can only see the crater from a far, but can’t approach further past the path.
The best time to visit is during the late spring to early autumn, as during the winter the crater lake freezes and gets covered by snow.
Explore Nearby
Top Attractions
Okama Crater
Volcanic crater walk
Ginzan Onsen
Charming riverside onsen town with historic inns and winter magic.
Aoba Castle
Sendai's hilltop castle ruins with city views
Zao Onsen Ski Resort
Famous ski resort with snow monsters and relaxing hot springs.
Fukuura Island
Pleasant walk on a scenic island in the Matsushima Bay
Hours and Admission
- Hours: Sunrise-Sunset (May - end of October)
- Closed: November through April
- 550JPY - Toll road fee (price may vary based on vehicle)
- Average Time Spent: 1 hour
- Official Website
Accessing Okama Crater
Due to the highly remote nature of mountain, accessing Okama Crater can be challenging.
From Yamagata Station, take the train to JR Kaminoya-Onsen Station and take a free shuttle bus for 60 mins. Get off at the katta parking area and take the Zao-Katta ski lift, which will take you within a few minutes walk of the crater viewing area. Noting that there are only 2 free shuttles per day from April-November.
From Miyagi, there is a once daily bus on weekends from Shiroishi Zao station, which takes 1 and a half hours, and costs 1960JPY one way.
Alternatively, if you have a car, there is access from both the Yamagata and Miyaji side. The carpark has plenty of parking availability, and is only a short walk from the crater. There is however a toll to go up the Okama for cars, and is open May to October.
