We went to Showa Kinen Park today, a beautiful, enormous city park. We walked for hours and still did not see everything. They have a paddle boat lake, a water park, bike rentals, lots of different play areas for kids, as well as lovely picnic spots (and a gorgeous flower festival in the spring).
Japanese custom is to remove your shoes when entering a bathroom and wear the slippers provided. This bathroom, at a public park, was so clean you could have eaten in there! (We later decided that we must have used a staff bathroom, because none of the other bathrooms had slippers. Ooops! Oh well, at least we followed the proper protocol!)
It was a great day!