Since opening in November 2004 with a secret show by The Killers, this sleek, modern boite has become a playground for young Hollywood players.

Established in 1922, Montmartre Café is supposedly where the term "see and be seen" was coined. That motto still holds true for today's Montmartre Lounge, home to Leonardo DiCaprio's Aviator premiere party, Alicia Keys' Grammy after-party and more. Though the multi-roomed playpen is located on the opposite corner of the Hollywood & Highland complex, the Montmartre Lounge is hard to find: The front entrance is completely blacked out and the sign is an "ML" painted on the small, white awning. (Enter around the corner on Highland Avenue and climb the spectacular staircase to get inside.) Even on the colorful, candlelit balcony, which serves as an outdoor lounge and the path inside, the hustle and bustle of Hollywood Boulevard already feels miles away. Two lounges are decorated with brown velour couches, a VIP section is outfitted with white vinyl seats. On the large dance floor we once spied Efren Ramirez, who played Pedro in Napoleon Dynamite, showing off his theatrical dance moves to 50 Cent. —Alexandra Le Tellier