Portland, Maine.
It's quite walkable, with smaller but quite interesting museums and plenty of good food & drink at reasonable prices.
If you rent a car with your points you can hit even more neat museums outside of Portland (Maine Maritime Museum, Farnsworth Art Museum), drive up and down the coast, and also do as much (non-strenuous) hiking as you'd like (on the coast or inland). Maine also has a ton of flea markets.
You could also probably use your points to stay here:
http://www.marriott.com/hotels/trave...wn-waterfront/