So, I haven't visited this church but I sure hope I get there some day. It is in Barcelona, Spain and was begun in the 1882 and is still under construction. One of the great Catalan architects, Antoni Gaudi, became involved in the design in 1883 and continued to work on the church until his death in 1926. He left extensive plans for its completion.
The website for the church has an amazing collection of images that are really worth checking out. I particularly love the towers and side naves. Here are just two images from their collection: