I would say for sure one of the biggest places to avoid is Havana, Cuba because as amazing as it may seem it is also one of the most dangerous cities ever and to be exact is is the 6th most dangerous city so that should be something to avoid for sure and a second thing would be Varadero because of the fact that its one of the main places that involve the Cuban mafia and last but not least and maybe try to avoid the hotel named Brisas del Caribe Hotel just because there are rumors that it is a bad hotel. Hope this helps :D