Lake Tōya, or Tōyako (洞爺湖), is a stunning caldera lake located in the Shikotsu-Tōya National Park, in Southern Hokkaido Prefecture. Lake Tōya was formed by volcanic activity over 100,000 years ago. It’s nearly circular and spans about 10 kilometers across, and is extremely deep, with a maximum depth of 180m – one of the deepest lakes in Japan. 

The area around Lake Tōya is geologically active. Mount Usu, an active volcano, and the dramatic, dome-shaped Mount Showa-Shinzan, which formed in the 1940s, are nearby. Both offer hiking trails and viewpoints for breathtaking views of the lake and surrounding area.

In the middle of Lake Toya, you can find Nakajima Island, which translates to “Inner Island”. The Island of Nakajima is uninhabited as it is a nature reserve. Wild animals, such as deer, roam free in their herds through the dense woods. There is a clearly marked hiking trail on the island, and the abundance of nature makes venturing out to Nakajima well worth it. 

One of the more notable attractions around Lake Toya, are the variety of cruise options offered by Toyakokisen, with cruises that venture out to Nakajima Island the large island in the center of Lake Toya. 

The area around Lake Toya is a geothermal hot spot, resulting in geothermal sites and onsens which are plentiful in this area. Along the waterfront, you can even find naturally headed footbaths to soak in for a few moments and refresh yourself.  From late April to October, nightly fireworks displays light up the sky over Lake Tōya, viewable from most onsen baths. The experience of soaking in a hot spring while watching fireworks is unforgettable.