Are you looking specifically for a studio or an outdoor location? I live in the Boston area as well and been looking for places for outdoor shoots.
In looking, I've discovered that it has to be a place where you know that people are OK with shoots, IE making sure no cops are around in case you have cosplay weapons.
It also depends on what kind of tone are you looking for. Are you looking for a more industrial setting or outdoorsy park feel? Its hard, considering you might have to ask permission for certain locations, ie around schools or around the Common. The older building feel can also be found in the South End as well. For parks, there is Harvard Park right near Harvard Square that might work. I did a film shoot a while back for it.
If you need a studio and are willing to pay, Boston Studio Photography has some decent rates and a great basement look and an outdoor landing as well...
Hope this helps.