Marina Abramović and Ulay's Naked Performance at Bologna Museum in 1977

On June 2, 1977, Marina Abramović and Ulay performed 'Imponderabilia' at the Galleria Comunale d'Arte Moderna in Bologna during the Settimana Internazionale della Performance. The artists stood naked in a narrow doorway, forcing about 350 visitors to squeeze between their bodies to enter the museum. Police eventually intervened to stop the event. Ulay described the work as forcing a split-second decision on which performer to face, while Abramović stated, 'If there were no artists, there would be no museums; we are living doors.'