Spoletosfera, Geodesic dome and theatre in Spoleto, Italy

Spoletosfera is a geodesic dome of prefabricated triangular metal elements joined at nodal points, about 21 metres in diameter, standing in a green area between viale Matteotti and viale Martiri della Resistenza. It needs no internal walls or pillars to stand, and a tarpaulin cover turns it into a space for performances, conferences and exhibitions.

Spoletosfera was donated to Spoleto by Richard Buckminster Fuller in 1967 for the tenth Festival dei Due Mondi, while Giovanni Carandente curated a Fuller exhibition covering 1927-1967. Fuller had patented the geodesic dome in 1954. He inaugurated the dome himself with a lecture on rational mechanics and demonstrations of "mind ballets". In 1968 Mario Ceroli placed a ten-metre pyramid of ice blocks under it, topped by an iron ball of burning coke swinging like a fire pendulum.

The dome functions as a venue where theatrical performances and art presentations draw audiences into an unusual spatial experience. This setting shapes how visitors perceive and engage with the events taking place inside.

The dome stands in a green area between Viale Matteotti and Viale Martiri della Resistenza, south of the historic centre and in front of the Casina degli Ippocastani. It is reached on foot from the centre. Since 2008 it has been lit at night by about 105,000 white LEDs on 750 metres of transparent tube.

Fuller inaugurated the dome himself with a lecture on rational mechanics and demonstrations he called "mind ballets". In 1968 Mario Ceroli placed a 10-metre pyramid of ice blocks beneath it, topped by an iron ball filled with coke that swung like a fire pendulum for nearly a month of the Festival.