Lake Mashu
A Caldera Lake Surrounded by Steep Cliffs Along a 20 km Shoreline
Lake Mashu is a caldera lake located in Teshikaga, eastern Hokkaido, within Akan-Mashu National Park. The lake has a circumference of approximately 20 km and a maximum depth of 212 m.
One of its distinctive features is that no major rivers flow into the lake. The lake is called “Kamui-to” (Lake of the Gods) in the Ainu language. Its water is known for high clarity, and the lake surface can appear deep blue depending on weather and light conditions. This color is known as “Mashu Blue.”
The lake is surrounded by steep caldera walls rising about 150 to 350 m above the water. Access to the lakeshore is restricted. Fog is more likely to occur around June and July, sometimes covering the lake’s surface. The appearance and extent of the fog vary with weather conditions.
Three observatories are located around the lake: First Observatory, Third Observatory, and Ura-Mashu Observatory. Each offers a different view of the lake. The First and Third observatories are located on the southern side, while Ura-Mashu Observatory is located on the eastern side.
- * Please note that the text shown on this page includes machine translations.
- Category
- With friends
- Solo trip
- Guys' trip
- Girls' trip
- Couple
- Travel style
- Activities & Outdoors
- Winter scenery, drift ice
- Lake and marsh, waterfall, pond, dam
- Red leaves, scenic spots, observation platforms
- Natural scenery, spectacular views
- Skiing, snow activities
- Visit seas, rivers, and lakes
- Travel Inspiration
- Enjoy spectacular views
- Adventure Travel
- Picturesque spots
- Nearest airports
General Information
- Postal code
- 〒088-3222
- Address
- 北海道川上郡弟子屈町原野
- Telephone Number
- 015-482-1530（Lake Mashu Rest House）
- Car Park
- 140 spaces, charged
- Directions
- ● By bus: About 25 minutes from JR Mashu Station
● By car: About 120 minutes from Doto Expwy Ashoro IC - Website
* Information on facilities is subject to change. Please check each official website for the latest information.
![[Memanbetsu Airport IN → Kushiro Airport OUT / 2 Nights 3 Days] World Natural Heritage Site Shiretoko, Lake Mashu, Lake Akan, and Kushiro Marshland! Eastern Hokkaido Greedy Course to Fully Enjoy Nature](/lsc/upfile/course/0000/0024/24_1_s.jpg)
