The world's first museum of varves opened in Wakasa-cho, Fukui Prefecture. The varves in Lake Suigetsu are a global standard measure for age determination. Sediments with varves piled up continuously in the lake bed for 70,000 years unravel mysteries of ancient history.
Varves refer to the sediment with characteristic annually laminated sediment piled up in the lake bed. One new layer made up of light and dark colored stripes is formed each year and this striped pattern is piled up alternately. The color difference arises from different types of sediment depending on the season.