"Candela’s stimulus for the form of Los Manantiales Restaurant in Xochimilco, Mexico City came from Colin Faber, who was working with Candela at Cubiertas Ala. Faber had made a rough sketch that somewhat resembled the final form of the restaurant; Candela liked the idea, so he took it and redesigned it into a more graceful shape.1 The form of the shell was a play of the hypar with free curved edges, that is, the edges of the shell are parabolic and free of any edge stiffeners that would conceal the thinness of the shell. The groined vault consists of four intersecting hypars, a structure that he had not yet attempted.
The Cosmic Rays Laboratory, Candela’s first hypar shell, has curved edges just like those of the restaurant in Xochimilco. Where the laboratory has two saddles, one in front of the other, the restaurant belongs to a type of shell structure called groined vaults. The groins are the valleys in the shell formed at the convergence of the intersecting hypars. The restaurant was not Candela’s first groined vault. He had designed a few others before Xochimilco, but none so striking.”