

This pond is located in
hibiya parkHibiya-park is designed with western style.
But this pond and garden around the pond have traditional Japanese style.
That place was a moat of former edo-castle ever.
You can see stone wall over the pond in these photos.
By the way "shinji (心字) literally means a character (symbol) that indicate "heart".
The shape of the pond looks like figure of a kanji symbol, "心 (kokoro, shin)".
(If you look at the pond from above the pond.)
This idea came from Zen (禅).
(Note)
These photos were taken on April 29 , 2009.