It's on the southeast corner, by the four points hotel. I assume it was added around the time they rebuilt the interchange following the I-10 expansion.

I'm curious if anyone has ever actually visited it. It's very strange. Seems like a very awkward location. Hard to relax listening to the roar of cars at one of the busiest highway junctions on the planet. It would make a fantastic dog park since it is fenced but it has a sign that says no pets.