Heiwa-no-mori Park Athletic Field

The entry fees are very reasonable for both children and adults, making it an inexpensive family outing.

The park offers a wide variety of 40 ninja-training-style obstacles, providing hours of active entertainment for kids and parents.

Beyond the athletic field, the park includes playgrounds, an archery range, sports courts, and a beach, offering diverse activities.

It's an excellent place for kids to burn off energy and get good exercise, with many climbing, jumping, and zipline-type activities.

Despite being outside central Tokyo, it's easily accessible by Keikyu or JR lines, making it a viable day trip option.