Lake Mashu
Lake Mashu, A Deep Caldera Lake In Eastern Hokkaido With No Inlet Or Outlet And Steep Walls, Known For Its Clear Water And For The Mist That Often Hides It, So That A Clear View Is Called A Stroke Of Luck. Seen From Viewing Decks, Not From The Shore. · Teshikaga, Hokkaido
Lake Mashu is a caldera lake inside Akan-Mashu National Park in eastern Hokkaido, near Teshikaga and Kawayu Onsen. No stream flows in or out, and the steep crater walls drop straight to the water, so there is no shore to walk and no beach. Its water is among the clearest in Japan, which gives it a deep blue colour on a good day. The catch is the weather: fog rolls over the rim very often, especially in summer, and a clear view is often called a stroke of luck. You look from viewing decks on the rim, commonly the Dai-1 and Dai-3 observatories - confirm which are open - not from the water. The lake is not for swimming or boating. The older Ainu name is said to be Kamuy-to, the lake of the gods - confirm. It suits drivers and bus riders already in the Akan, Kushiro or Kussharo area, and it is a poor choice on a short trip with no spare day. Allow 30 to 60 minutes at a deck. It is worth the detour in clear weather and mildly disappointing in fog. Lake Akan lies nearby, and some roads close in winter.
Lake Mashu viewing decks (Dai-1 and Dai-3 observatories), Teshikaga, Kawakami District, Hokkaido, a bus or drive from Kawayu Onsen or Kushiro, Teshikaga, Hokkaido, Japan
The viewing decks are outdoors and open all day with no gate, though shops and cafes at the observatories keep daytime hours, commonly about 9:00 to 17:00 in the warm months and shorter in winter - confirm. Some roads and services close or reduce in winter because of snow, so check before driving. By public transport, buses link Kawayu Onsen and Mashu on a limited seasonal timetable, and the last bus back leaves early in the afternoon - confirm. A rental car or a sightseeing bus from Kushiro or Kawayu is the easier option. Nothing needs booking. Carry cash for the shop and a warm jacket.