Richard Serra Born in 1939 in San Francisco (USA). Lives and works in New York (USA). "Olson" (1985-1986), a master-piece of unstable equilibrium. Serra's main medium is steel. His works set up a relationship with the surrounding architecture or the urban space. The contrast between their massive presence and their precarious equilibrium can also elicit a fascination of a spiritual order, despite the simplicity of the means utilised.