From a high school classroom to a Hello Kitty-themed dungeon to the inevitable, and cliched, sexy nurse, the options are endless and often creepy. Misty Keasler captured this surreal underworld in Love Hotels: The Hidden Fantasy Rooms of Japan.

Keasler discovered the establishments while teaching English in Japan. She was captivated by the unusual way they facilitated sex, offering everything you need to make the most of your time—there are vending machines with vibrators, sex swings, and handcuffs affixed to the walls. It's a strange blend of kitsch and fantasy, and their locations are numerous.

"I was just taken by sheer number of hotels," said Keasler. "At the time in 2004 and 2005 there were 30,000 love hotels in Japan. Compare that to 7,000 Starbucks in the state of Texas."

Though the hotels are ubiquitous (nowadays there are some 37,000 in all) and constantly busy,  Keasler says people rarely discuss them and blush when they do. Because of this, hotels strive for discretion—private waiting rooms protect you from prying eyes should you arrive early, and automated systems ensure there are no nosy desk clerks to betray your confidences.