Kasai Rinkai Park
The star attraction here is the Diamonds and Flowers Ferris wheel, the second-tallest in Japan. The ride takes you on a 17-minute trip to the apex, 384 feet above the ground, for a spectacular view of the Tokyo bay area. On a clear day you can see all the way to Mt. Fuji; at night, if you're lucky, you reach the top just in time for a bird's-eye view of the fireworks over the Magic Kingdom, across the Kyuedo River. As a bonus, all Ferris wheel gondolas are private. The park also has an observatory looking out over Tokyo Bay, in addition to the Tokyo Sea Life Park aquarium, a bird-watching center, and some so-so beaches.