As a result of the Big Dig project and development of the Seaport district, it's possible to run about 14 miles from Charlestown to the UMASS Boston. Most of it very pleasant along the water! We've detailed several sections
The 6-mile segment from Pleasure Bay to UMASS in South Boston is our favorite section of the Boston waterfront for running. Includes Castle Island, Carson Beach, JFK Library, UMASS Boston campus.
The Boston Harbor Islands National Park features 34 islands and 35 miles of undeveloped shoreline. Spectacle Island is the most run-able, with 5 miles of trails. Deer Island, accessible by land, has a 2.6 mile path with great views.