Hossawa falls is one of the famous falls in Tokyo metropolitan prefecture. It has been selected one of the "100 best falls in Japan". In the very cold season the waterfall is known to freeze. Recently it seldom freez perfectly. You can see the current view of the fall by the livecamera set in front of the falls by Hinohara village (operation 6 am to 6 pm JST).
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.