Though the most famous attraction of Zao is soft rime in winters, Okama takes the place of the most popular site during spring to autumn. Okama is a circle crater lake surrounded by the three mountains of the Zao Mountain Range, i.e. Kattadake, Kumanodake, and Goshikidake. This lake was named Okama after Japanese traditional cooking pot (kama) from its shape, and has been beloved by all. This lake also has another name of "Goshikiko" (lake of five colors) since its surface of emerald green changes its color according to the sunlight. No creatures can inhabit here due to its highly acidic lake water. This is an exclusive lake in the world in terms of its water layer structure where the water temperature decreases to 2 °C until 10 m deep and then increases in further depth.
There have been 26 eruptions in Zao up to date, and the latest one occurred on February 15, 1895. The lake was 63 m deep when measured in 1939, but it was gradually buried over years due to the collapse of Goshikidake cliff walls, which resulted in the size of maximum depth of 27.6 m, average depth of 17.8 m, circuit of 1,080 m, 325 m east to west, and 325 m north to south in 1968.
Get on the Zao High Line (tolled road) from Zao Echo Line, and drive up to the park of Zao Mountain Peak Restaurant, the final point of the road, and you will find the view deck where you can see Okama after a few-minute walk from there. Zao Echo Line is closed during a certain period of winter.
Address: Inside Zao National Park, Zao-machi, Miyagi
Phone: 0224-34-2725 (Zao Tourist Association)
Hours open to visitors: 8:00 - 17:00
Closed: A certain period of winter
Directions: (Bus) An hour and 47 minutes on Miyako Bus bound for Zao Katta Mountain Peak from JR Shiroishi Zao Station (runs only in Saturdays, Sundays, and national holidays)
(Car) An hour from Shiroishi Interchange, Tohoku Expressway