The Emerald Necklace consists of a 1,100-acre (4.5 km2; 450 ha) chain of parks linked by parkways and waterways in Boston and Brookline, Massachusetts.

It was designed by landscape architect Frederick Law Olmsted, and gets its name from the way the planned chain appears to hang from the "neck" of the Boston peninsula.

Some links of the Emerald Necklace not only offer an opportunity for recreation in a wooded environment, but are also ecologically important urban wilds that provide nesting places for migratory birds and improve the air quality of the city.

Olmsted's vision of a linear park of walking paths along a gentle stream connecting numerous small ponds was complete by the turn of the century.

[5] Over the past decade,[clarification needed] almost $60 million in capital expenditures for parks and waterway improvements have been made in the Emerald Necklace by the City of Boston and the Town of Brookline.

To steward the Emerald Necklace’s 1,100 acres of parkland extending from Boston’s Back Bay through Brookline and Jamaica Plain to Franklin Park in Dorchester, the conservancy works in collaboration with its partners on advocacy, maintenance and restoration, education and access, and promoting park stewardship through volunteer and youth programs.

Unfortunately it has taken a lot of conservation efforts in order to limit this plant's spread, making it more difficult to achieve Olmsted's vision.