The Serpentine Gallery Pavilion commission is an ongoing programme of temporary structures by internationally acclaimed architects and designers and is unique worldwide. Pavilion architects to date are: Kazuyo Sejima and Ryue Nishizwa, SANAA, 2009; Frank Gehry, 2008; Olafur Eliasson and Kjetil Thorsen, 2007; Rem Koolhaas and Cecil Balmond, with Arup, 2006; Álvaro Siza and Eduardo Souto de Moura with Cecil Balmond, Arup, 2005; Oscar Niemeyer, 2003; Toyo Ito with Arup, 2002; Daniel Libeskind with Arup, 2001; and Zaha Hadid, 2000.