Boston Waterfront is a 4 mile point-to-point trail located near Charlestown, MA and is good for all skill levels. The trail is primarily used for hiking and walking and is accessible year-round.
Lots to explore, including Faneuil Hall/Quincy Market, the New England Acquarium, the North End and parts of the Freedom Trail to name just a few.
This is an easy walk along a waterfront area that varies between parks, older neighborhoods, and historic properties converted to (e.g.) condos. It also includes the aquarium, shopping and harbor cruise docks. Their is plenty of historic, shopping and dining interest adjacent to the waterfront, and public transportation is convenient for access and departure.