Weirdest HorseShoe Court? Ever.

We were walking in Golden Gate Park the other day and came across the this weird horseshoe court. It is about 80 feet by 30 feet, sand pits and stakes along the long sides, and paved in the middle. it's also recessed, as there are 6 foot high walls around the entire thing, with cement seating on the ledge. Creepiest of all, there is mural/sculpture of a disemboweled horse near the front.