Okama Crater Lake
Okama, meaning an honourable cauldron, is the inactive volcanic crater on top of Mount Zaō, located in Kawasaki, Miyagi, on the border with Yamagata, Japan. While local people call it affectionately Okama, the visitors tend to call it Goshiki-numa, meaning "Five Color Pond", because its color changes depending on the time of the day, the weather, or the season of the year.
Okama Crater Lake is situated at the height of about 1600 meters above sea level. According to the 1968 survey, its east-west and north-south diameters are both 325 meters, and maximum depth is 27.6 meters.