They didn't accept walk-ins during summer. It's possible that they aren't busy, now that many schools are open, and so may accept walk-in.
Reservation is best.....if before labor day weekend
Reservation setup is easy. They sell out times even on days with open slots. Just showing up isn't a good idea.
It's always better to have a reservation or you could end up waiting hours for a spot. If you're okay with waiting... pack a picnic lunch, it's fantastic to just hang out there. It can never hurt to call first to see how busy they are before going.
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