As if Mt. Fuji weren't enough of an attraction in itself, Hakone has blossomed into one of the largest spa towns in Japan. The area is also one of the most accessible to the casual visitor, having catered to Tokyo weekenders for decades. Besides the hundreds of inns with their own onsen, a few springs are devoted to day trippers. Tenzan is a large onsen complex complete with cedar baths, outdoor baths and the popular "massage waterfall". Sit under it for five minutes and you'll want to take one home.