In 2008, Swiss architects Herzog & de Meuron and Chinese artist Ai Weiwei joined forces to design the celebrated Beijing National Stadium for the Olympic Games. In 2012, the team came together again for the Serpentine Gallery's acclaimed annual commission, as part of the London 2012 Festival, the culmination of the Cultural Olympiad. Their pavilion takes visitors beneath the Serpentine's lawn to explore the hidden history of its previous pavilions. Supporting the structure from below, eleven columns symbolize past pavilions, and a twelfth represents the current one. The pavilion's interior is clad in cork, to evoke the excavated earth, and is built as a network of pathways and trenches. Herzog & de Meuron and Weiwei's archaeological approach creates a space that invites visitors to look beneath the surface of the park as well as back in time to the inspiration of earlier structures.