I see this thread has picked up some responses, since I looked at it yesterday.
I lived in Newport for three years, with the understanding it was from 1960-1963, so none of this may still exist, but Newport is more than citywalks and big mansions.
Touro Synagogue. If not the oldest Jewish synagogue in the U.S., then one of the oldest.
Redwood Library. If not the oldest public library in the U.S., then one of the oldest.
Whatever Tower. I call it that, because I can't remember its name, but it's claimed it was built by everyone from the ancent Phoenicians to Benedict Arnold's grandfather for everything from a watchtower to a windmill.
It was the home of Oliver Hazard Perry, "We have met the enemy, and they are ours," naval hero of the War of 1812, and his younger brother Matthew, who did much to open up Japan to the West 40 years later.
It was a site of a major battle of the American Revolution.
It was a stop on the Underground Railroad.
Newport Creamery, where you can/could buy some of the best ice cream you'll ever eat.
The White Horse Tavern.
It was/is the home of the Newport Jazz Festival.
Take what was the ferry, now a bridge, over to Jamestown and walk along the beach and pick up broken piences of glass and crockery worn smooth by the action of the tides.
Despite the crowds, go in the spring, go in the summer, go in the fall, but don't go in the winter. You'll freeze.
Actually, Adventures by Disney offers a tour of Newport through its Beantown & Big Apple tour.