Kasai Rinkai Kouen is the largest park in central tokyo. The park is very big and it if you are looking to get out of the city this is a good place to visit. You can see families having picnics here and you could also check out their sea life park. The park has a beach, grass area, ferris wheel and the aquarium. There are also stands along the park selling Japanese food such as Melon Pan, Okonomiyaki, kakigouri and Takoyaki. You could spend a whole day here without spending much. The view itself is perfect!
Near the Tokyo sea life aquarium is the diamond flowers ferris wheel which is known to be the second highest in Japan. The life park itself also has a bird sanctuary where you could see photographers taking pictures of the birds. The birds here are also friendly and are not afraid of interacting with humans unlike the birds in Tokyo which children tend to chase around.
How to get there: The Keiyo Line stops right at Kasai Rinkai kouen station coming from Tokyo Station. Which costs ¥210
Fees: The Tokyo sea life aquarium would only cost you ¥700 and the ferris wheel is also ¥700. The sea life park is closed every wednesday and the the ferris wheel is closed on the 4th and 5th wednesday in January and every wednesday of February. You should check the schedules before going in the case of Holidays.