Shikotsu-Tōya National Park (支笏洞爺国立公園 Shikotsu-tōya-kokuritsukōen) is a national park (983 km²) in the central part of the island of Hokkaido, Japan. There are many lakes and active volcanoes in the park. Showa-Shin-zan, Usa-zan, and Tarumae-zan are the more well known among the active volcanoes. These volcanoes are also responsible for some popular onsens.
Surrounded by hills, the dominant feature is Mount Fuppushidake (風不死岳), an Ainu name cleverly written in kanji as "Wind-never-dies Peak". The main town is
Shikotsu Kohan (支笏湖畔) - is a small village on the eastern side of the lake. There is a small tourist information office here, near the bus station.
Toyako Onsen - is a small Onsen town on the shore of Lake Toya, There is an excellent Visitor's Centre about 100m from the bus station. All sorts of interesting information can be found there regarding the history of the area and explanation of volcanic activity, etc. There is also a separate volcano exhibition in the centre which costs ¥600 to enter.
Sapporo's New Chitose Airport (CTS) is quite close to Shikotsu and there are direct buses to Shikotsu Kohan (55 minutes, ¥920), as well as from Hokkaido's capital Sapporo and the major port Tomakomai. There are also buses connecting Toyako Kohan to Sapporo (¥2700, 2.5h).
Toya Station is located along the main Hakodate-Sapporo line, but it's another 20 minutes by bus from there to Toyako Onsen. A taxi ride to Toyako Onsen costs about ¥2200.
As in much of Hokkaido, buses are infrequent, so your own wheels or hitchhiking are the best ways to get around. Motorized boats are, thankfully, not allowed on the lake. Sightseeing boats departing from Toyako Onsen offer cruises around the lake.
Lake Shikotsu. A caldera lake surrounded by active volcanoes and an unreal mossy gorge, 44 kilometers in diameter, Lake Shikotsu is famed for the clarity of its water.edit
Lake Toya, (Next to Mt. Usu.). Right next to Mt. Usu, one of Japan's most active volcanoes; you can see what happened to buildings, cars, roads, etc when a volcano erupts A near-circular lake 10 kilometers in diameter, Lake Toya is famed for the clarity of its water, and it never freezes in winter thanks to the geothermal activity of the region. Along with nearby Lake Shikotsu, it forms a part of the Shikotsu-Toya National Park. This is a caldera lake, the remains of a very large volcanic eruption that has hollowed out ground, where the water is highly mineral rich.edit
Inside the Moss Canyon
Moss Canyon (苔の洞門 Koke no dōmon). On the south side of the lake, these are in fact two canyons, both several hundred meters long, densely carpeted with thick, green moss. Free entry and well worth a visit.edit
Mt. Usu (有珠山 Usuzan). This 737m peak is the most active of the lot, with 4 major eruptions in the last 100 years. The latest in 2000 showered much of the neighboring town of Toyako Onsen with ash and debris. The mountain has quieted down now, and there are trails leading to newly created craters on the west side of the mountain. The most notable is Nishiyama Crater Trail (西山火口散策路), where you can see what happens to buildings, cars, roads, etc when a volcano erupts. It is also possible to hike around the southern half of the main crater if one takes the cable car on the east side to the rim. You can see a former public hot bathing house half-inundated with mud, a block of public housing whose first floor is completely buried on one side, and a part of a former bridge which was pushed by the mud some 300 metres from its original position. Just as you start this walk, there is a small hut with a man inside giving away maps of hiking in the Toyoko region in various languages including English. For some reason, the Visitor's Centre does not have this extremely useful brochure.edit
Shōwashinzan (昭和新山). This mountain, literally "Showa New Mountain", popped out in a local farmer's field in December 1943 and, two years later, had reached a height of 402 meters. It is located right next to the cable car valley station on the east side of Mt. Usu.edit
Being a volcanic lake, there are a number of hot springs in the vicinity. Both hot springs below also offer lodging. Noboribetsu is located here, and is one of most famous hot spring resort on Hokkaido, and Toyako Onsen is, as the name suggests, also packed with Onsens.
Itō Onsen (いとう温泉), ☎ +81 0123 25-2620, . 10AM-4PM. Located on the northern side of the lake, 3 km west from the main road towards Sapporo. Notably primarily for a pleasant outdoor rotenburo with great views of the lake; it's a little strange to stand by the lakeshore completely naked, but hey, you're just a flyspeck if seen from the other side.¥700. edit
Kyūkamura Shikotsu Onsen (休暇村支笏湖温泉), . A somewhat clinical hot spring resort not far from Shikotsu Kohan.¥700. edit
Hot Spring Hotel Marukoma (丸駒), Shikotsuko Poropinai 7, Chitose (A few kilometers SW of Itō Onsen, at the end of the side road.), ☎ +81 0123 25-2341, . This is a lakeside hotel and onsen. There are indoor and outdoor baths, and also saunas.Bath ¥1000. edit