In several of Moore's later monumental bronzes such as Knife Edge Two Piece there are echoes of the massive rock formations in the countryside around Leeds, such as Adel Rock, which the artist knew as a boy. The Foundation's cast of this sculpture is the artist's and is marked 0/3. Artist's copies form the core of the Foundation's collection. Two further casts are in public collections: one is in Queen Elizabeth Park, Vancouver; the other belonging to the City of Westminster, is sited outside the Houses of Parliament and is often seen as a backdrop during filmed interviews with the press. An even larger but reversed image version, Mirror Knife Edge (1977), was commisioned for the entrance to the new east wing of the National Gallery of Art, Washington DC, designed by I.M. Pei.