
The linear park is a long, narrow green corridor for recreation and movement, often following a watercourse, ridge or former transport route. Frederick Law Olmsted's Emerald Necklace, begun in Boston in 1878, linked parks along the Muddy River into a continuous chain that also managed flooding. The idea was revived for disused infrastructure in New York's High Line, built on an abandoned elevated rail viaduct and opened from 2009.
Greenways stitch parks, neighbourhoods and habitats together while providing walking and cycling routes apart from traffic. The reuse of derelict infrastructure as linear park has become a signature model of contemporary urban regeneration and ecological design.