The Carlyle
If Diana was in town, you could bet that she was staying at the iconic Carlyle Hotel. The Upper East Side staple was a favorite of hers, so much so that Prince William and Duchess Kate chose to stay there as a tribute when they came to visit the city in 2014. It also happened to be the site of her now-infamous, top-secret meeting with JFK Jr. in 1995. Although rumors swirled about a saucy rendezvous, the official story is that they met to discuss a potential cover shoot for JFK Jr.'s magazine, George. Ultimately, she politely declined his offer.