The 281-acre Arnold Arboretum of Harvard University in Jamaica Plain, founded in 1872, is part of the historic Emerald Necklace and home to more than 15,000 plants. Visitors can explore the park on their own, or enjoy guided tours, and other events.

America’s oldest public park, founded in 1634, is located in the heart of the city and measures nearly 50 acres. The park offers sculptures and memorials, free Shakespeare on the Common, carousel rides, and year-round events at the Frog Pond. The park also marks the start of Boston’s Freedom Trail.

Visitors can board a ferry and head out to one of the Boston Harbor Islands to hike, bike, swim, camp, and explore. Spectacle Island features miles of walking trails and panoramic views of the Boston Harbor while Georges Island is home to the Civil War-era Fort Warren.

OK, so it’s not a castle. And it’s not an island. This 22-acre South Boston park was an island at one point, but land reclamation projects have since joined it with the mainland. The grassy parkland is enjoyed by joggers and dog walkers and is home to the 19th-century Fort Independence, a National Historic Landmark.

The 64-acre Charles River Esplanade, named one of the 10 best riverwalks in America by USA Today earlier this year, offers miles of paved trails for runners and cyclists along the Charles River and playgrounds for kids. The Hatch Memorial Shell is an open-air performance stage that hosts movie and music nights and the Boston Pops Fireworks Spectacular every Fourth of July.

This 4 ½-acre park by Boston Harbor offers beautiful flowers, a picturesque trellis, maritime views, a playground, and plenty of space for relaxing and watching folks stroll by. Free outdoor movies are shown throughout the summer.

With the eastbound and westbound sides of Commonwealth Avenue flanking it on either side, the 32-acre Comm. Ave. Mall, as it is affectionately called, is a favorite dog-walking area for local residents. It is also another link in the Emerald Necklace, joining the Public Garden with the Fens.

The historic Emerald Necklace is a 1,100-acre chain of urban parks that links more than a dozen city neighborhoods stretching from the Back Bay to Dorchester. It was created by Frederick Law Olmsted, the founder of American landscape architecture. Visitors can explore the parks on their own or take part in a guided bike tour or educational walk.

This 8.2-mile waterfront trail connects a series of parks in the communities of Dorchester, Hyde Park, Mattapan, and Milton. Parks and reservations in the Greenway include the Dorchester Shores Reservation, Neponset Park, Neponset River Reservation, Pope John Paul II Park, and Senator Joseph Finnegan Park.

Just across the street from Boston Common is the 24-acre Public Garden, where visitors will find flowers, statues, and the city’s famous Swan Boats. Near the Charles Street and Beacon Street entrance is the tribute to Robert McCloskey’s “Make Way For Ducklings’’ children’s book: a set of nine bronze ducks by artist Nancy Schön. The famous ducks are often dressed up and included in special celebrations.