http://www.bbc.co.uk/news/technology-31923259 (3D Printing)
The Basílica i Temple Expiatori de la Sagrada Família is a perfectly astonishing church in Barcelona, Spain.
A cathedral is the seat of a bishop and the Sagrada Família is not that, so instead in November 2010 Pope Benedict XVI consecrated and proclaimed it a minor basilica. I've only ever seen it in pictures or on the TV, but I would call it a masterpiece of the imagination.
The very famous Catalan architect Antoni Gaudí got involved in the construction of the Sagrada Família in 1883, a year after construction started, and then took the entire project over. What we see now (and in the future) is his vision. The entire project is funded entirely by private donations and, for this reason (plus World & Civil wars) progress has been slow.
The video at the BBC is of the way that 3D printing is helping to speed construction. It also involves stunning shots of the interior.