The construction of Barcelona’s Gothic cathedral began in 1298. However, thanks to civil wars and plagues, building dragged on at a pace that makes the Sagrada Família project look snappy: although the architects remained faithful to the vertical Nordic lines of the 15th-century plans, the façade and central spire were not finished until 1913. Indeed, the façcade continues to cause problems: although it’s one of the newest parts of the building, it’s crumbling, and roughly a third of it is being taken down and painstakingly rebuilt with the same Montserrat stone that was used for the original.