The essay explores the relationship between Calderón de la Barca's auto sacramental, El gran teatro del mundo (c.1636) and a contemporary rewriting of it, Das Einsiedler Welttheater (2007), by the Swiss novelist and dramatist, Thomas Hürlimann (b. 1950). The relationship between in two plays is considered in the contexts of the German Romantic re-discovery of Calderón and of the Einsiedeln theatre festival tradition. Although Hürlimann's play contrasts significantly with its Spanish source, it is argued that, in many respects, he may be seen to be, paradoxically, faithful to Calderón.