There are a lot of stone walls around the Stonington, CT area, there was one road in particular (I'll have to lookup the name, can't remember it) which was in a scene of Mystic Pizza which has a lovely bower of oak trees and old stone walls on both sides. Eastern CT is pretty good for that kind of thing.

You might also want to take a look at a guided tour (about the only way you can see these) of Gungywamp in Groton, CT, just a few miles from Mystic. I see on the photos page they are claiming them as colonial structures, but there are mysterious runes, and apertures which correspond with the sun at certain times of the year, etc. It looks as though they are distancing themselves from any kind of mystical connotations. It is a fair, but short hike and really a calm, yet sort of eerie palce to visit. I sat on a boulder which was littered with tiny garnets. There is an old legend about an Indian princess jumping to her death in the Thames River up around there and I don't care what they are saying now, some of that stuff pre-dates colonial times. I have a book written about it by one of their high mucky-mucks which points this out. One of the unusual runes is an early Christian symbol from the 6th or 7th century! Most interesting palce to visit.