Lake Biwa

Biwa covers about 670 square kilometres, a sixth of Shiga prefecture, and is around four million years old - one of perhaps twenty ancient lakes in the world that have held water continuously long enough for their own species to evolve in isolation. Roughly sixty are endemic here, including the Biwa trout and several freshwater mussels, and the lake supplies drinking water to something like fourteen million people downstream in the Kansai basin. Around the shore: Hikone Castle with an original keep on the eastern side, Enryakuji on Mount Hiei above the south-western corner, the floating torii of Shirahige, the island shrine of Chikubushima reached by boat, and a long cycle route, the Biwaichi, that rings the lake in about two hundred kilometres. Fish is the local food - funazushi, fermented crucian carp, is a very old and very strong-tasting preparation that predates modern sushi.

What you actually see

• An ancient lake - about four million years old with some sixty endemic species.
• The Biwaichi - a cycle route of roughly two hundred kilometres around the shore.
• Shore landmarks - Hikone Castle, Enryakuji, Shirahige's torii, Chikubushima.
• Funazushi - fermented crucian carp, an old preparation that predates modern sushi.

When to go

April to November; spring and autumn for cycling. Two days.

Honest expectations

The lake is very large and the shore is developed in stretches - the scenic parts are not continuous. Funazushi is genuinely pungent and divides opinion sharply. Summer humidity is heavy. Invasive species have displaced much of the native fish population.

Nearby

Kyoto is south-west over the hills; Hikone is on the eastern shore.