Land area: 99,473 ha
Designated on May 16, 1949
The main feature of Shikotsu-Toya National Park is the spectacle of nature. It includes Noboribetsu, one of the major hot spring resorts in Japan, and some active volcanoes.
There is also Mt. Showashinzan which has undergone a dramatic process of the formation. Just about sixty years ago, the land which had been used as barley fields, was upheaved and erupted to form a volcano. Visitors can enjoy a fascinating landscape with varied topographic features.
Shikotsu-Toya National Park is located in the southwest part of Hokkaido and is composed of three parts: the area from Lake Shikotsuko to Noboribetsu, the area which includes Lake Toyako and Mt. Usuzan, and the area centering around Mt. Yoteizan. The main features of the park are volcanoes and lakes.
Lake Shikotsuko is a caldera lake in the shape of a cocoon. It is the second deepest lake in Japan, reaching depth of 360 m. The lake is also notable as it is the northernmost ice-free lake in Japan. It usually does not freeze because of its depth and waves in the winter caused by strong winds. Around the lake, a range of mountains stretches north and south, each of which are more than 1,000 m high.
It is believed that Shikotsu caldera was created about 30,000 years ago and that the topography of Hokkaido changed significantly because of the large pyroclastic flow that erupted at the time. For example, it is thought that the mouth of the Ishikarigawa River on the Pacific Ocean was closed up by the pyroclastic flow, causing the river to change channels and flow into the Japan Sea.
Noboribetsuonsen Spa is one of the major spa resorts in Japan and is known for its diverse spring qualities and abundant yield of hot water. Visitors can see bountiful geysers of fumarolic gas and hot water here.
Lake Toyako is an almost round caldera lake, which extends for about 11 km east and west, and about 9 km north and south. It has a cone-shaped island in the center, Nakanoshima Island. At the lakeside, plains stretch out to inhabited areas and farmlands. It has topographic features different from that of Lake Shikotsuko, which is amid a range of high mountains. Mt. Usuzan (732 m) which rises on the south of the lake restarted volcanic activities in the 17th century and has erupted repeatedly since then. It continues to be very active to date. Mt. Showashinzan (398 m) on the east side of Mt. Usuzan was formed just about sixty years ago. From 1943 to 1944, the land, which had been barley fields and forests, rose and erupted. After the eruption, a lava cone rose to form a mountain. The mountain is a genuine active volcano as it is still fuming.
Mt. Yoteizan (1,898 m), whose beautiful figure is reflected on the water of Lake Toyako, is also an active volcano. It is called Ezo-Fuji, which means Mt. Fujisan in Hokkaido.
The main vegetation in the park area is a mixed forest of coniferous trees such as Spruce (Picea jezoensis) and broad-leaved trees such as elm (Ulmus davidiana Planch. var. japonica). Mt. Yoteizan has a unique feature in terms of vegetation. As it is a lone mountain, one can observe the vertical distribution of vegetation on the mountain starting with the broad-leaved forest area at the bottom. On the mountaintop, communities of alpine plants can be seen.
The park is a habitat for various forest animals including brown bears and Ezo martens native to Hokkaido. Lakes in the park are home to many waterfowls which fascinate the visitors.