I grew up in Miami and lived there many years in various areas. The neighborhood west of Biscayne Blvd, in the area of the port , known as 'Over town' could be dangerous, particularly at night, but in daylight as well. If a person got lost and ended up in the midst of it at a traffic stop or whatever.
The park that is adjacent to the port on Biscayne is also a place I wouldn't want to be after dark or unarmed. Than again, I haven't been down there in twenty years or more but back in the '70s and '80s there were people killed or maimed down that way. It may be different nowadays.