Doing some filing work I came across a photograph I took during a visit to the Supreme Court a couple of years ago: In one of the courtyards that bring light to inner-facing windows (see an image of the plan) there's a badminton court. At least, I'm reliably informed that's what it is:
click image for full view
The thought of justices whacking away at shuttlecocks is a mighty pleasing one, though I suspect that the court is used by staff or the clerks. The net seems a bit low to me, though, so maybe it's for counsel to unwind in an unchallenging setting.