What Should Greg Michaels Do on His Vacation?

What should I do and where should I go with my mother and possibly my uncle during vacation next week? 

I have vacation starting Friday going through the Memorial Day weekend. No, we’re not really going anywhere except for a quick jaunt to Boston Friday just so it’s easier for us to pick my mother up at Logan first thing Saturday morning.

We will be spending a few hours in Boston Saturday. We'll check out the Boston Common and possibly Quincy Market if time allows. We'll also have lunch at my favorite Boston restaurant that I've been to so far, Fire & Ice.

It's always nice to have a visit from Mom, she’ll be here for eight days, May 16^th through the 24^th. To add to the excitement my uncle may be coming up from Maryland with his girlfriend, so this begs the question, what to do?

Aside from Freeport and the other shopping areas around, what at low cost of or free is cool to do in central or southern Maine. I’m thinking, of things to do that are an hour or less of a drive from Lewiston-Auburn. Further is ok if the idea is right.

Ideas don't need to be totally child focused as two of the three will have school but we will have a three year old with us.

If you have any ideas for mini adventures, let me know.