The Breakers - this is the Rockefeller’s summer home in Newport. It’s open for tours, and though I don’t recall the prices being crazy, it’s definitely been a while.
It’s so ostentatious and over the top, but beautiful, and full of wonderfully made things.
I think it’s interesting to consider our modern billionaire class as equivalents to Rockefeller’s gilded age.
Oh, and while you’re in RI make sure to get a Del’s frozen lemonade.