Naughty Atami is the Shizuoka resort with the beachfront soaplands and other salacious establishments. It's got the fraying Hihokan (literally: House of Secret Treasures), likely the world's least scholarly sex museum, with its holographic strippers and a Marilyn Monroe mannequin that exposes itself on demand. Enjoy "Carry On" movies or pens with pictures of girls whose bikinis fall off when you tilt them? You'll love Naughty Atami.

But then there's Serene Atami, the Izu Peninsula idyll that sits in what was once a volcano's crater, and still enjoys enough bubbling sulfuric water to warrant a place on the nation's Three Great Hot Springs list.

Serene Atami offers dreamy outdoor baths with views across Sagami Bay. Tokugawa Ieyasu (1543-1616) used to frequent this one with his children, and legend has it that the old shogun ordered his poor underlings to haul barrels of water back to Edo Castle.