Tlön, Uqbar, Orbis Tertius by Jorge Luis Borges

Background: http://en.wikipedia.org/wiki/Tl%C3%B6n,_Uqbar,_Orbis_Tertius

The Story: http://art.yale.edu/file_columns/0000/0066/borges.pdf

Found through a quote on the Urbit mailing list.