Koishikawa Botanical Gardens

One of two botanical gardens run by the Graduate School of Science, University of Tokyo, Koishikawa is a stately patch of private parkland that dates back to the Meiji Restoration and has the rambling ruins to show for it. The living plant collection proudly boast 4,000 different plant species, some of which are up to 300 years old. The area is open to the public, and makes for a lovely stroll on a sunny day. Recommended.