During your visit to Balboa Park, do not miss this gigantic, world-class musical instrument. Believed to be the largest outdoor pipe organ in the world, this impressive structure was built in 1915 by sugar magnates John D. and Adolph B. Spreckels. Year round, as many as 2,000 people can sit and hear the Sunday afternoon concerts. At other times, local musical talent is displayed. All concerts are free of charge.