Antoni Gaudi took the architectural style known as Art Nouveau a step farther, even, some have argued, into absurdity. The fanciful and outrageous buildings he created in Barcelona have become landmarks, the signature attractions of this Catalan city. Foremost is The Sagrada Família church, officially the Temple Expiatori de la Sagrada Família or the Holy Family Church of the Atonement. One of Europe's most unconventional churches, it is also unfinished, so as you look down from its tower you can see the work in progress below.