Wang Shu says that the design represents an intersection of “three valleys crossed by large stairways – two on the inside and one on the outside”. The internal walls (also in concrete) were moulded with bamboo canes as well. The use of this unusual technique, as with the use of wa pan for the walls, meant that the builders had to be specially trained: they had lost their own traditional knowledge. This unusual regained skill, however, now means that they are much in demand in their own market