One of the most striking features of the Barcelona Pavilion, a 1986 replica of the temporary structure designed by architect Ludwig Mies van der Rohe as the German Pavilion for the 1929 International Exposition, is a red curtain visible behind a transparent glass wall. This detail, the only primary color in the composition, is inextricably linked to the pavilion’s representational legacy and to the 1986 structure’s authenticity as a reliable artifact. The modernist and classical aestheticizing and politicizing of the pavilion, however, have prevented us from looking beyond the red curtain. Here lies the conceptual epicenter of Mies’s work. Why has the Barcelona Pavilion endured? What was the purpose and motivation of reconstructing a temporal structure that had very little explicit purpose beyond its own archi-political sovereignty? Do the answers lie in our subconscious need to experience firsthand a genuine utopian artifact? And if so, what exactly constitutes a utopian architectural artifact? This article examines the twentieth-century utopian tradition in architecture and places the Barcelona Pavilion at its epicenter.