Who in San Diego knows what and where the Balboa Park Activity Center is? And who knew that table tennis is the #2 sport in the world? I didn't know any of these things until now. This is actually not a good photo because the building above is not the Activity Center at all, it is behind where I was standing and the building in the photo is the old Naval Hospital. The Activity Center is a gym on the east side of the park and has courts for table tennis, badminton, volleyball, and other sports.