Belcourt of Newport is one of Bellevue Avenue's stranger mansions, built for Oliver Belmont with an enormous carriage hall at its heart. Compared with the Breakers or Marble House, it feels more idiosyncratic: part Gilded Age statement, part architectural experiment, and still shaped by restoration work.
It is worth adding if you have already seen Newport's headline houses and want a less predictable angle on the same social world. Tours are the way in, and availability can change with preservation work and private events.