Antique Real Photo Postcard. Identified as the Spreckels Organ Pavailion in Balboa Park, San Diego, California. Card #16 / 15051. Divided back, EKC stampbox, unused. Condition: This is an original photo postcard, not a copy or reproduction. It is in excellent condition. Comments: Spreckels Organ Pavilion houses the open-air Spreckels Organ in Balboa Park, San Diego, California. The Spreckels Organ is the world's largest pipe organ in a fully outdoor venue.