Shikotsu-Toya National Park

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 two lakes each has a lakeside hot spring town.

• Shikotsuko Onsen (支笏湖温泉). A small village on the eastern side of the lake. There is a small tourist information office here, near the bus station. (updated Aug 2015)
• Toyako Onsen (洞爺湖温泉). A small hot spring town on the southern shore of Lake Toya. There is an excellent visitor center about 100 m 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 center which costs ¥600 to enter. (updated Aug 2015)

Sapporo's New Chitose Airport (CTS) is quite close to Shikotsu and there are direct buses to Lake Shikotsu (55 minutes, ¥920), as well as from Hokkaido's capital Sapporo and the major port Tomakomai. There are also buses connecting Lake Toya to Sapporo (¥2700, 2½ hr).

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.

No fees required. Permits not generally required.

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 km in diameter, Lake Shikotsu is famed for the clarity of its water. 
• 🌍 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 km 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. 

• 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. 
• 🌍 Mt. Usu (有珠山 Usuzan). This 737-m 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. 

• 🌍 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 m. It is next to the cable car valley station on the east side of Mt. Usu. 

• In season, you can rent swan boats for paddling out on the lake Shikotse, there are also boats for rent on lake Toya.
• Fishing is popular.

Toyako Onsen town has the usual array of Japanese restaurants. There are some basic stalls near the Morappu Camping grounds as well.

• Lapland (ラップランド Rappurando), 10 minutes south of Shikotsuko Onsen, ☏ +81 123-25-2239. A quirky but pleasant log house minshuku. A night with two meals and a trip to the nearby onsen is just ¥4900. 
• Morappu Camping (モラップキャンプ場). A basic lakeside campsite popular with fishermen, with toilets, rental equipment and some food stalls nearby. Reservation required. ¥500 per person. 

You're in bear country. Don't feed the bears. Make noise and they'll avoid you if possible, they are usually more afraid of you.