Lake Toya is in Shikotsu-Toya National Park in the southwestern part of Hokkaido. It is said to be one of three fine landscapes in Hokkaido. It is a caldera lake with a circumference of about 40 km and the 3rd largest lake in Japan. The caldera where the lake is located was formed by an eruption about 100,000 years ago. There are some active volcanoes on the southern outer rim of the caldera, which include Mt. Showashinzan and Mt. Usuzan.

Ezo deer inhabit on Naka-no-shima Island in the middle of the lake. Lake Toya is a renowned place for bird watching. Geese and other water birds stay here in winter because it never ices. In May, when winter birds leave for the north, mandarin ducks and other summer birds come flying.

Another thing that is popular in recent years is “Lake Toya Long-Run Fireworks Nights,” which is an on-the-lake fireworks display held every night from April to October.