We found some sea captains mansions that had been converted into interesting museums in Searsport, Maine many years ago. May be bread and breakfast places by now. Mystic Seaport is worth spending a 1/2 day if you have an interest in olde tyme seafaring lore like I am. Pulling a toad in east coast cities is probably more bother than it's worth. Boston had no RV parking in the city but had a number of options for shuttle and tour buses, walking tours, etc. Best to do some research before your RV tour.