Colònia Güell church, Antoni Gaudí, discussed by Santiago Calatrava (1992).

Building Sights Europe series: personal reflections on 20th-century European architecture. Spanish engineer and architect Santiago Calatrava assesses Gaudi's famous work. "To be at Colònia Güelll," he says, "is to experience Gaudi's architectural obsession - an obsession that transcends the ordinary and reveals to us something of the sublime."