I'm a Bostonian, grew up going to George's Island. I love it and recommend it to my out-of-town friends visitng during summer months. Why? Well, there's a boat ride involved. Not an hours-long whale watch, but enough of a ride to see the Harbor and, more importantly, see the view of the City from the Harbor. For kids, there are lots of exciting places to explore and fields for picnics and frisbee games. For adults, there's the history of the island, the ecology, and the larger history of the Harbor itself. The ferry is not that expensive. Pack a picnic lunch as the food choices on the island are limited. You'll also need good weather and sunscreen. This is a seasonal activity.