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.

This primary path in the park is about 2.25 miles.

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

This puppy runs about 2.5 miles around Cambridge's water source. Different buses go by, and the Alewife Red Line stop isn't that far away.

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 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. The park itself cuts through the lower reaches of Boston into Dedham.

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.

This path runs from the Back Bay-South End borderlands all the way through to Forest Hills in Jamaica Plain.