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Built on a disused raised rail track, New York's High Line park has attracted millions of visitors since it first opened to the public in 2009.

Now, a group of developers are hoping to use optical technology to pipe sunlight underground and turn a dilapidated tram terminal on Manhattan's Lower East Side into the world's first underground park.

For the proposal to go ahead, the team will need permission from the city authorities to convert the space and raise an estimated $60m (£38m).

³ÉÈËÂÛ̳ Travel Show's Jo Whalley meets the people behind the Lowline proposals and visits a lab showcasing the technology which could help make the project happen.