Designed in Neoclassical style by Ireneo Aleandri, the Sferisterio is an open air stadium erected by private subscription in the 1820's originally built as a stadium for Pallone col bracciale. The arena had been used for occasional theatrical events since 1871, but since about 1914 the opera began to be performed there. The current "Macerata Opera Festival" (MOF) takes place in this location, the acoustics are surprisingly good though its rather unusual shape for musical performances.