If you don't want to pay to see all the mansions, you can also take the path along the cliffs and see them from the outside. Well-furnished and surrounded by greenery and flowers, this walk is popular with locals, who often walk their dogs here. You can see five or six mansions with huge gardens that open directly onto the trail.
Leaving Newport, you can either take the 238 north, or if you have a little more time, take the 138A that goes to east along the ocean front. There are beautiful views, especially at sunset, of the creeks and deserted beaches, fringed by big houses. There are a number of luxury hotels on these shores, too.
Newport is where the New York rich came in the early 1900s, to show off their wealth by building palaces that served as second homes. Most cost several million, are made from the finest materials, and are equipped with all mod cons. Many of the houses are fully public now, and you can tour them accompanied by a comprehensive audio guide that tells the story of the family who lived in each house, but also of the architecture and furniture. The town itself is a small harbor with a main street lined with shops. The mansions are hidden in the streets on the hills. There is a lot of greenery in the city, small parks and squares that make for a really nice visit.