For more than a century, Bostonians have taken great delight in the Esplanade, one of the many green gems designed by Frederick Law Olmsted. While most famous to outsiders as the locale of the annual Fourth of July Boston Pops concert, it's embraced year-round by locals who love the way its paths hug the Charles River and offer the most attractive views of Cambridge. Pedestrian bridges give access to Beacon Street and also crisscross the inner lagoon (which now features gondolas!), so there can be as much variety in your jog, walk, or cross-country-skiing excursion as you like.

Despite being home to urban horrors -- one of the most infuriating rotaries in the Commonwealth, looming high rises, and a congested shopping plaza -- Fresh Pond is also synonymous with green space. Fresh Pond Park offers a 2.5-mile jogging path surrounding a natural reservoir amid wooded landscapes. Birdwatchers seek out the park, as do skiers, dog owners, and others who long to escape city sprawl without leaving the city.