In the shadow of the incredible success of New York's High Line – the public park stretching the length of the former elevated rail line skirting Manhattan's lower west perimeter – architecture firm Raad Studio have been quietly re-imagining another vast section of disused urban space in the city.

While it might not have quite the same ring to it, the subterranean Lowline project is causing quite a stir in design, urbanism and architecture circles.

An artist's impression of New York's proposed Lowline subterranean park.

The proposed project will convert an abandoned, 4000-square-metre former trolley terminal that lurks beneath Manhattan's Lower East Side neighbourhood into the world's first underground parkland, with trees, plants, seating and sunlight, which would be channelled down into the space via a system of reflective panels and fibre-optic cables.

The Lowline Organisation has launched a Kickstarter campaign to help fund the development of the park.

thelowline.org