It is fine today, so many people enjoy playing in this field. This field is called "Min-na no harappa" in Japanese, "Min-na" means everyone and "harappa", field. A 360 degree panorama of this place was already taken by Mr. Shizuya, who is one of the pioneer of the 360 degree panorama photos in Japan. But I uploaded this because it shows many Japanese people enjoy their holiday delightfully.
Tama area is the name of the western part of Tokyo Metropolis. It consists of 26 cities, 3 towns and a village. A lot of people (about 4 milion) live in a eastern half part of the area. However, there are many mountains in the western part of Tama area, and there are very little flat land. Many hiking spots are in the western area, so you can enjoy walking on the trail, camping, and so on. If you see the beautiful mountain scene, you may not believe this is also in Tokyo.