Mar del Plata is the Atlantic City of Argentina, plus beaches. In the sweltering summer months, a large portion of those fleeing nearby Buenos Aires lands here and the beaches are wall to wall flesh. In the off-season, the city is a quiet seaside town. There are many nearby private beaches, a casino, and lots of places to eat out.
In November, the city hosts a film festival, and shortly thereafter is overrun with tourists. If you're in Argentina to party spring break style, this is the place for you in the summer, right down to beach party television coverage.