Central Library, UNAM

Juan O'Gorman designed the library from 1948 with Gustavo María Saavedra and Juan Martínez de Velasco, and it was built from 1950 on sixteen thousand square metres of the Pedregal lava field. The parti is blunt: put the stacks in one windowless block, lift it on a stone plinth, and treat the four blind faces as a single surface. That surface carries "Representación histórica de la cultura", four thousand square metres of mosaic laid in naturally coloured stones gathered across the country, with tinted glass standing in for the blues O'Gorman could not find. The north wall is the pre-Hispanic past, the south the colony, with the Ptolemaic and Copernican systems set against each other; the east is the Revolution and the atomic present, the west the university itself. Read frontally the whole block reads as a mask of Tláloc. UNESCO inscribed it with the central campus in 2007.