https://phys.org/news/2018-10-image-kyoto-osaka.html

Whilst almost three-quarters of the country is mountainous, less than 10% is covered by bodies of water. Northeast of Kyoto, we can see Lake Biwa, located in the neighbouring Shiga Prefecture. This is the largest freshwater lake in Japan, covering an area of 672 sq km.

The area is famous for being home to Narezushi, the precursor to modern-day sushi. The dish is thought to have originated in southeast Asia around the second century CE. People began to prepare it in Japan between 8 and 10 CE. Funazushi, using nigorobuna fish, typical of the Lake area, is prepared by fermenting and preserving the fish with rice and salt in barrels for up to a year. The result is a strong-tasting dish, often compared to blue cheese and accompanied by sake.