Lake Itomori

Lake Itomori is a lake in Gifu, Japan. The town of Itomori lies around this lake.

Formation
The lake was created as the result of a fragment from Comet Tiamat crashing into the town 1200 years prior to the events of the film.

Real-life location
While the lake is fictional, it is based on Lake Suwa, a lake in the Kiso Mountains, in the central region of Nagano Prefecture, Japan.

Its coordinates are 36°02′54″N 138°05′03″E.