The Festival dei Due Mondi — Festival of Two Worlds — has been Spoleto's defining event since composer Gian Carlo Menotti founded it in 1958. Running for two weeks in late June and early July, it brings opera, theatre, dance, and music to venues across the old town: the Roman amphitheatre, the Piazza del Duomo, the Teatro Caio Melisso, and courtyard stages set up for the occasion.
The festival transformed Spoleto from a quiet provincial town into an internationally recognised arts destination. Outside festival time, its infrastructure remains — the Teatro Caio Melisso (a perfect horseshoe opera house rebuilt in 1880) operates year-round, and the town is full of galleries and spaces that exist partly because of the festival's permanent presence. If your visit coincides with the festival, booking early is essential; if not, the town is considerably more peaceful and half the price.