There is an arc of light under the Grand Central clock on 42nd and Park that has been illuminating interesting and unexpected activities for decades. In the 50’s it was Walter Cronkite recording headlines for CBS, in the 60’s it was a 65 foot astroturf ski slope built by a Hungarian immigrant, and for a while after that it was the playground of more wayward turf when in the hands of Mr Trump. But these days the capacious cavern has become home to the most well placed tennis court in the city.

The Vanderbilt tennis club has public courts so anyone can play. Even Serena Williams. Apparently she was a regular during the last US Open, warming up for the next win. You just need to book in advance and be prepared to pay between $80 and $250 per hour depending on the time of day. ( Racquets are an extra $10 each…) The space may be a long way from Cockaleechie, and there are sounds of girls rather than galahs, but the sheer inspiration of the location with that iconic arched window, makes it a great spot for a few hits. You can even pump and spin from an overviewing gym level if you want to warm up and watch.

Grand Central is like a magic box, full of surprises. Original elevators transport you between the tracks and the concourse and the court, with the arrow pointing the way. But you may also find the doors opening to a restaurant or to the new bar spilling out from the Campbell Apartment, or even to the train driver’s lunch room on the fifth floor. Just be sure to read the signs – Mr Cronkite’s sharpie is still on the job…