Millions stroll in New York's 'park in the sky'

One of the runaway hits of this past summer in New York has not been on Broadway - instead it has been at a most unusual park which is attracting millions of visitors from all around the world.

The disused elevated railway track that runs through downtown Manhattan now offers commuters and tourists alike a peaceful escape from the chaos on the busy city streets below.

The inside story of New York City's so-called "park in the sky'' is about to be told in a book called High Line.

Michael Maher took a stroll through the park to find out more.