Pierre Cabanne asks him if he has ever engaged in any artistic activity during the twenty years he has been spending his holidays in Cadaqués. Duchamp says that he has, because every year he would rebuild an awning to create shade on his terrace. 

In The Engineer of Lost Time, interviews with Marcel Duchamp by Pierre Cabanne, edition Assírio&Alvim 2002

The marking of the implantation point/the epicentre of the installation

The first bag membrane is unwound and stretched over the floor surface, over the entire implantation area, oriented towards the position of the access to its interior.

PVC bags are piled up all around, filled with sand to serve both as ballast, and as a bench.