One of the twelve moats surrounding the Imperial Palace and a favourite spot amongst the tourists for its stunning scenery. It is especially beautiful in spring when you can see cherry blossoms. The trees are lit up during the night and create an outstanding flower path for people to enjoy and take pictures of.
Many locals and tourists come here to relax while enjoying the nature here. People often set up tents and offer others food, snacks and other refreshments. It is a great spot for a run, and you surely should not miss it even if it's not in the middle of cherry blossom season. It is a good way of seeing downtown Tokyo but also enjoying the peace and quiet.
In case you don't feel like walking, you can hop into a paddle boat and see the beautiful scenery from the water.
The moat is a short walk away from the Kudanshita and Hanzonmon metro stations.
The moat is best visited during the flower blooming season in April.
Wikipedia http://ja.wikipedia.org/wiki/%E5%8D%83%E9%B3%A5%E3%83%B6%E6%B7%B5
Official website http://www.env.go.jp/garden/kokyogaien/english/index.html
Address (Unnamed Road), Tokyo, Japan
Coordinates 35°41'9.547" N 139°44'41.871" E