The largest high school basketball gymnasium in the world is the New Castle Fieldhouse, located in New Castle, Indiana. Boasting a staggering seating capacity of over 8,400 to 9,300 spectators, this massive facility accommodates more fans than the home arenas of numerous major NCAA Division I college basketball programs. It stands as an enduring monument to the profound cultural phenomenon of "Hoosier Hysteria" and high school sports passion across the state.