The island of Manhattan is home to the greatest concentration of private clubs in this country, and no, we are not talking about the velvet-roped doors of the Meatpacking District. These elite institutions date back to the early nineteenth century, modeled after the gentlemen's clubs of London and retain the codes of behavior from that era. The buildings are reverent but nondescript, the fees are astronomical, and the dress code is de rigueur. Here are 7 members-only clubs, where the upper echelon of New York Society can freely mix business with pleasure.

It's no secret that sometimes a girl just needs a little time away from the boys. The crop of popular female-only clubs around the country takes the concept of ladies' night to whole new levels. Now London is jumping on the bandwagon, opening up its first girls-only luxury health club this week. With a boutique service that handles all Net-a-Porter.com purchases, Grace Belgravia is definitely the chicest health club we've ever heard of. For those of you in need of girl time, but who can't quite jet off to London, click through for some New York-based girls-only clubs to try.

Social clubs and country clubs around the country are eyeing "Echo Boomers," or Generation Y-ers, to join their ranks as junior members. Count the George Town Club at 1530 Wisconsin Avenue among them.

The club tapped socialites Diana Minshall, 29; Ashley Taylor Bronczek, 29; and Kendall Arney Vincent, 28, to head their "young professional membership" campaign, which launched last night with a happy hour and a tour of the club. The drive targets socials under 35.

Prospective members trickled in last night to the informal Grill Room--the only room where jackets are not required--and picked at cheese, fruits and nuts elegantly laid out on a large silver platter. Cocktails were served with George Town Club napkins. General Manager Brian Armstrong gave two tours to accomodate the group, which grew to about 30 people after two hours. A second prospective member happy hour is taking place next week. Only people picked by the three young ladies could attend one of the prospective member happy hours. More»

Membership dues are in the thousands of dollars, clubhouses are often unmarked, membership lists kept top secret. The New York Social Club is still going strong after 174 years, unhurt by recessions, depressions, and even (gasp) the admittance of women. Some of the clubs aren't so secret anymore (ahem, Soho House), but that doesn't make it any easier to obtain membership... More»