What do you get when you mix brains and sex? New York's one and only Museum of Sex (commonly referred to as MoSex). Amazingly enough, this cultural and educational institution didn't open its doors until 2002. MoSex occupies 15,000 sq. ft. at 27th Street and Fifth Avenue in what used to be New York's red light district and features exhibitions about the history of sex, from pornography to fetishism to sex trade. The Museum of Sex also houses the world's largest and most comprehensive archive of heterosexual pornography in literature and film, which was donated by a former Library of Congress archivist. Unlike other local museums, anyone under 18 must be accompanied by an adult to visit MoSex.