Okutama.

Okutama is a town popular for fishing, camping, hiking, kayaking, etc about 40 minutes outside of Tokyo.
It's easy to forget that you're still in Tokyo with all the mountain scenery around.
There are many outdoor onsens (hotsprings) and mountain temples - quite peaceful..if you can ignore the scores of other campers, families, crying babies, University students setting of fireworks, the kayaking competition and randow tourists and drunks all around you.
My tent's the orange one.
Even camping is crowded in Tokyo..