These are a collection of some of the mansions in Newport I saw walking around the Bellevue Avenue, Newport Cliff Walk areas. In years past, you could not take photos inside the mansions, but I read that has changed now. There is a trolley in Downtown Newport you can take to this area (parking might be difficult in the summer).

Within the "mansions area" of Newport, there is also Salve Regina University, containing some mansions of its own. I don't know the boundaries, but it's all fairly impressive.