The cryptogram is one of the most popular symbols of the passion facade. It is an enigmatic square with sixteen numbers that allows one to count up to 310 different combinations, always adding up the number 33 -the Chirst's age at his crucifixion (most important event in the Passion).

The cryptogram was created by Subirachs. Gaudí never made it clear how exactly he wanted the scupltures of this facade to appear. When Subirachs accepted the task of completing the facade (1987), he did so given the condition that he would be allowed to complete the facade in his own style, so as hot to have the sculptures confused with those of Gaudí, and so as to further Subirachs' own artistic career aswell.