The island includes 2.6 miles of shoreline and two miles of pathways. You can actually bike to it through Winthrop as its name is a misnomer: It's really a peninsula.

There are up to 6 miles of trails in this park, which also has fabulous views of downtown Boston and Newton.

This 9-mile trail runs between Leverett Pond and Jamaica Pond; it also connects with other paths.

You can start here or in nearby Paul Revere Park and do the approximately 1-mile cycle to the Navy Yard (and back).

The path runs an epic 23 miles, on both sides of the river, through Boston and Watertown, all the way to Waltham.

This approximately 5-mile loop around the Harvard research site comes with some nifty views of Boston via the 200-foot-high Peters Hill. It also connects to other paths.

This 11-mile path follows the first footsteps of the Revolution, and runs through Cambridge, Arlington and Lexington.

Paths in this park run from just under 2 miles to more than 6.

There are several miles of paths along the river that zip you through Winchester, Arlington, Medford, Somerville, Everett, and Chelsea (though mostly Somerville and Medford).

A reader swore by this monster: more than 200 miles of bike paths that connect with other bike paths, many entry points available via commuter rail.