Acapulco, Mexico
Credit: Holger Leue / Getty Images

The original sun-kissed retreat for Hollywood big shots back in the '50s, this well-developed Pacific coast spot remains a popular destination and a standard port of call for luxury liners. Despite plenty of polished glitz and glam though, Mexico's well-documented drug cartels are now a presence, and so periodic outbursts of ultra-violence have infiltrated the city, with bold, daylight shootouts in the open streets. The most notorious of a few years ago involved heavy caliber weapons and grenades–during an attack on police headquarters.