Cost$150m ($171m today)
Millions come to the site to visit every year.
New homes and offices have been built because of the new park.
Solved the problem
Come up with a way of re-using an old railway line in New York.
Turn an abandoned city railway line into a modern public garden space
The High Line is a 2.3km long public park in New York City built on a disused elevated (raised) railway on Manhattan's West Side.
The High Line railway – a landmark of the city – was built in 1934 to carry trains delivering goods to businesses in New York's industrial district. It connected directly to stores and warehouses, allowing trains to unload inside buildings.
The line saw a drop in traffic as companies switched to moving freight by the improving interstate highway network. The rail route was abandoned by the 1990s.
A local campaign to save the railway from demolition saw the creation of a non-profit group - Friends of the High Line - and a proposal to turn the track into a park.
Supporters included fashion designer Diane von Fürstenberg who raised $150m for the scheme. Work began in 2006.
Designers took inspiration from the 4.8km long Promenade Plantée in Paris. The 10m high elevated park – the first in the world - was built on a 19th century viaduct between the Bastille and the Bois de Vincennes in 1993.
The High Line opened in sections from June 2009. Section 3 opened in 2014 with completion of the final section expected in 2018.
The park has a contemporary feel with a 'keep it wild' planting scheme – created by master of this style, Dutchman Piet Oudolf.
The scheme has become the most popular tourist attraction in New York with 8 million people visiting every year.
The High Line
The High Line is a 2.3km long public park in New York City built on a disused elevated (raised) railway on Manhattan’s West Side.
Video courtesy of CSX.
Did you know …
Woody Allen's 1979 film 'Manhattan' includes a shot of the High Line as Allen speaks the first line of dialogue: "Chapter One. He adored New York City".
Chase scenes from the Will Smith zombie movie 'I Am Legend' were filmed there.
The park has also been used for the HBO TV series 'Girls' and the 2012 film 'What Maisie Knew', starring Julianne Moore.
Difference the park has made
The High Line's success has encouraged the development of new homes and offices in the surrounding area. More than 11 projects were under construction by 2016.
The growth in new building has led to estimates that New York City will see around $4bn in private investment over the next 30 years as a direct result of the scheme.
The so-called 'High Line effect' has encouraged other US cities to create 'rail to trail' parks. Chicago's Bloomingdale Trail opened in 2015. Schemes under construction include Philadelphia's Rail Park and Atlanta's Belt Line.
How the work was done
Engineers faced many challenges in constructing a park on an elevated rail structure. Almost every aspect of a typical park had to be rethought for the scheme.
Many of the original steel rails were restored for use in the new park – reducing costs as well as the environmental impact of the project.
The scheme's designers kept many of the High Line's other original features. Echoes of the old railway such as riveted metal plates and 1930s ornamental guardrails can still be seen in the park.
The project team modified other aspects of the High Line to provide new features. These include a children's playground built of parts of the original structure covered with a special rubber coating.
As the plants for the scheme sit on a man-made floor – like a green roof – they were chosen for their hardiness and sustainability. There is also an irrigation system.