Kiyosumi Gardens was a pleasant surprise. The guidebook barely mentioned it, but there was a coupon for entrance to it on a hotel map we picked up. "A typical Meiji era garden with strangely shaped rocks and exquisite stones collected from all over the country." said the coupon.
Rocks just are not very exciting to me, but there was a large pond full of huge koi, and the garden was quite beautiful. I returned to the park several times. I also enjoyed wandering around in the neighborhood surrounding the park.