Lake Mashu (Teshikaga Town, Hokkaido) — Overview (History, Features, and Attractions)
Lake Mashu is a caldera lake located within Akan-Mashu National Park in eastern Hokkaido. The lake was formed in a deep crater formed by volcanic activity thousands of years ago, and the water is extremely clear, making it known for its beautiful "Mashu Blue" color. In the early mornings or under certain weather conditions, the lake's surface can be shrouded in thick mist, creating a mystical appearance that has earned it the nickname "Misty Mashu," and it has long been a popular tourist spot. Swimming and tourist boats are not permitted within the lake to protect it, and the main way to enjoy the view is from the surrounding observation decks.
Highlights
- First observation deck: This is the most easily accessible observation point, offering a panoramic view of the entire lake. Parking lots and toilets are available, and there is often a tourist information center and shop nearby.
- Third Observation Deck (view from the back): You can see a different side of the lake up close, making it a popular photo spot. You can observe in a calm atmosphere.
- Uramashu Observation DeckLocated on the north side of Lake Mashu, the scenery changes depending on the season and time of day, and the impression changes with the light in the morning and evening.
- Mashu Blue: A clear, deep blue color that can be seen on a clear day. When the conditions are right, the lake surface shines azure, making for a great photo.
- Lake Mashu shrouded in mist: Sometimes fog suddenly appears and covers the lake, creating a fantastical sight. The changing weather is a sight to behold.
Access (nearest station, transportation, etc.)
- Nearest train station: JR Senmo Main Line "Mashu Station" or "Station around Teshikaga". From Mashu Station, you can take a bus or taxi to the observation deck. It takes about 20 to 30 minutes by car from the station to the observation deck.
- busDuring the tourist season, sightseeing buses and local buses operate from Akan, Kushiro, and Abashiri. The number of buses varies depending on the season, so please check the timetable in advance.
- car: It's convenient to get there via the Doto Expressway (access from Akan or Nemuro). It's generally about an hour's drive from Kushiro City, Mashu, or Kussharo. There is free and paid parking at the observation deck, but it may be full during peak seasons.
- Airplane use: From within Hokkaido and elsewhere, it is common to fly into Memanbetsu Airport or Kushiro Airport and travel by rental car or bus. It takes about 1.5 to 2 hours by car from Memanbetsu Airport and about 1.5 hours from Kushiro Airport.
Estimated stay (estimated time required)
- Short-term viewing (First observation deck only): Approximately 30 minutes to 1 hour
- Visiting multiple observation decks, taking photos, and strolling: Approximately 1-2 hours
- Sightseeing in the area (including Lake Kussharo and hot springs): Half a day to a full day
Nearby spots
- Lake Kussharo: One of Japan's largest caldera lakes. Enjoy sand baths and hot springs (Kawayu Onsen area).
- Kawayu Onsen: A hot spring area famous for its sulfur springs. A convenient base for sightseeing in Mashu, perfect for lodging and bathing.
- Mount Io (Ainu name: Atosanupuri): A tourist spot where you can see geothermal activity and observe geysers and fumaroles up close.
- Bihoro Pass: A pass where you can enjoy a panoramic view of the surrounding area, including Lake Kussharo and the mountain ranges.
- Lake Akan area: Accessible by car from Lake Mashu. A wide range of Ainu culture and nature experience tours are available.
Things to be aware of (crowds, manners, seasonal precautions, etc.)
- The weather changes drasticallyFog can easily form around Lake Mashu, and visibility can change in a short amount of time. Even on sunny days, fog can suddenly appear, so please allow yourself plenty of time.
- The appearance of "Mashu Blue" depends on the conditions: Even on a clear day, the color of the lake surface changes depending on the time of day and lighting conditions. If you are taking photos, it is a good idea to check the color at multiple times of the day.
- Swimming and sightseeing boats are not permitted: For conservation reasons, swimming on the lake and public sightseeing boats are not permitted. Please refrain from entering the lakeside without permission.
- congestion: The observation deck and parking lot can get crowded during the summer tourist season, consecutive holidays, and during the autumn foliage season. If you plan to visit early in the morning or in the evening, you may be able to enjoy the view at a leisurely pace.
- Winter road conditions and clothing: In winter, snow and ice accumulate, causing road conditions to deteriorate. Studless tires and cold weather gear are essential. The area around the observation deck can be windy.
- Nature Conservation and MannersPlease be considerate of the natural environment by taking your trash with you, not touching plants or animals, and avoiding smoking or using fire outside of designated areas.
- Changes in facility information: Observatory facilities and bus operations may change depending on the season and government decisions. Please check the official tourism website or transportation site for the latest information before visiting.
Note: Lake Mashu is a place with fascinating natural scenery. Its appearance changes completely depending on the weather and season, so you'll make new discoveries by visiting at different times of the day or on different days. Checking the weather forecast and visibility information before visiting will increase your satisfaction.

