Getting greener, still

Out in the harbor, Spectacle Island, where much of the dirt from the Big Dig was dumped, is set to open this summer. Forty-two acres of new parks are planned for the easternmost end of the Charles River, to complement the Esplanade. And the crowning jewel will be the 30-acre strip of land from Chinatown to the North End, where the elevated highway once stood. That landscape is seen as the kind of opportunity for placemaking that hasn't presented itself since Olmsted.

It took the father of landscape architecture almost 20 years, from 1878 to 1896, to create the six parks considered the main elements of the Emerald Necklace: the Back Bay Fens, the Riverway, Olmsted Park, Jamaica Pond park, Arnold Arboretum, and Franklin Park. All told it's 5 miles and 1,000 acres of lawn, woods, fields, brooks, and pathways; in the area of Fenway Park, the system connects via the Muddy River and Charlesgate to the base of Commonwealth Avenue, a Paris-style boulevard with parks down the middle. That, in turn, connects to the Public Garden and finally Boston Common, the city's most Central Park-like open space, where cows grazed and revolutions simmered.

Though it's a perfect place to stroll or jog or bicycle today, the Emerald Necklace actually started as a flood and sewage control project, said Fred Schwartz, a ranger for the National Park Service stationed at the Olmsted homestead in Brookline. What Olmsted managed to do, he added, was combine park design, civil engineering, public health, transportation, and neighborhood development, producing a comprehensive system that gave rise to the profession of urban planning.