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Location in Japan
|Primary inflows||31 small rivers of the Kiso Mountains|
|Primary outflows||Tenryū River|
|Surface area||13.3 km2 (5.1 sq mi)|
|Average depth||4.7 m (15 ft)|
|Max. depth||7.2 m (24 ft)|
|Shore length1||15.9 km (9.9 mi)|
|Surface elevation||759 m (2,490 ft)|
|Settlements||Okaya, Suwa, Shimosuwa|
|1 Shore length is not a well-defined measure.|
The lake is the source of the Tenryū River. It ranks 24th in lake water surface area in Japan.
Lake Suwa is the site of an interesting natural phenomenon, The God's Crossing (御神渡り o-miwatari?). The lake has a natural hot spring under its surface. When the lake's surface freezes in the winter, its lower waters are still circulating. This results in ice pressure ridges forming in the surface ice, reaching heights of 30 centimetres (0.98 ft) or more.
Local tradition holds that the ridges are formed by the gods crossing the lake, when travelling between the various buildings of the Shinto shrine Suwa Taisha. Folklore says it is the guardian god of Suwa, Takeminakata-no-kami, leaving his sanctuary to meet with his wife, the goddess Yasakatome, joining the opposite bank by walking on frozen water.
Research on ice breakup on the lake and at the mouth of the Torne River in Finland suggested "global processes including climate change and variability are driving the long-term changes in ice seasonality."
- In the movie Kagemusha by Akira Kurosawa, Lord Shingen is buried in the lake.
- In Autobiography of a Geisha, Sayo Masuda tries to drown herself in the lake as a child, but hesitates because she believes a dragon inhabits it.
- In the anime Rurouni Kenshin, legend holds of an "Elixir of Immortality" that can be found somewhere in or around Lake Suwa. The main characters search for the elixir in the final season of the series and are followed by a band of evil German knights, seeking it for world domination.
- In the anime Kimi no Na wa by Makoto Shinkai the lake and scenery of Itomori town which is home to the heroine Miyamizu Mitsuha was modeled after this lake. 
- Sharma, Sapna; Magnuson, John J; Batt, Ryan D; Winslow, Luke A; Korhonen, Johanna; Aono, Yasuyuki (2016). "Direct observations of ice seasonality reveal changes in climate over the past 320–570 years". Scientific Reports. 6. doi:10.1038/srep25061. Article ID 25061. Retrieved 2016-05-07.
- Bell, Jillian (2016-04-27). "Industrial Revolution strongly tied to earlier thaws, later freezes: study". CBC News. Retrieved 2016-05-07.
|Wikimedia Commons has media related to Lake Suwa.|
"A View of Mount Fuji across Lake Suwa."