This is Hamana lake seen from outer sea. This was originally a freshwater lake but became brackish, due to a large earthquake and subsequent tsunami in 1499 that broke the sandbank which had been blocking the lake from the open ocean.

In those days, most travelers going down the Tokaido had to cross the lake by boat. The thick long wooden poles seen in the left foreground are part of the barricade protecting boats and ships from strong waves coming from the sea.

On the right, beautiful white Mt. Fuji is seen as if it is rising behind the dark mountains.