So much of Acadia is accessible to everyone. There is a park road that goes all the way around it. Check out the NPS site for Acadia. I was in Acadia years back with a family of non-hikers, and we were able to enjoy much (even though it rained the whole day we were there). I just was doing some research for a summer trip up there this year -- with any luck, we'll be there in mid-July.