I've been thinking about this, preparing my Campaign and all.
And, Miami and New Orleans were literally two of the first that popped into my mind, for those very same reasons.
Though, I also was thinking about San Francisco. Think about it for a second, San Francisco was home of the Gold Rush, bringing in thousands of people, and who knows what else with them? And, of course, Alcatraz is located off the shore of San Francisco. So, all sorts of Baddies were home there. I mean, if people leave an imprint when they die, think of all the lost souls wondering around on THAT island.