It features varve ranging from 70,000 years ago to the present, as found at the bottom of Lake Suigetsu.

It is a brackish water lake, with an area of 4.06 km², a perimeter of 9.85 km, and a maximum depth of 38.0 m, making it the largest among the five.

In addition, the lack of oxygen in the water at the lake bottom make it inhabitable to lifeforms, which also helps to keep the varve undisturbed.

Also, because of a fault running nearby, the lake gradually lowers its altitude and is never filled up with sediments.

Discount rates apply to a joint ticket with the Wakasa Mikata Jomon Museum.