Barcelona

6TH STREET. Although it can be difficult to locate, Barcelona is definitely worth your sleuthing efforts. The hip, underground (literally) club is a stylish boîte whose pale shell is enlivened with bold, colored lighting. Bars anchor the ends of the narrow space, and private areas are peppered about. Thanks to the preferences of individual DJs, the music changes each night, although variations of house are prominent. Patrons take their dancing seriously, so if you can hang, Barcelona's a great place to show off your moves.