The tall trunks of the towers change colors in places since Gaudí effectively­ used different stones in various sections, depending on the weight-bearing abilities of the rock type. It creates both an aesthetic resemblance to the light brown patches on ivory sycamore trunks and a practical solution. Near the top, the pillars literally branch out to support more ceiling. They are adorned with broken golden ceramics, perhaps a celestial view of fall leaves. It is a signature Gaudí decoration to use broken tiles put back together with spaces in between, harking back to when he recycled available materials in his earlier works, which can be seen throughout Barcelona.

TO GET THE LOFTIEST overview of the Sagrada Familia and its inspiring 360-degree views of Barcelona, I decide to head to the highest point nonworkers are allowed: the towers.

When the first tower was completed in 1925, Gaudí enjoyed "how that spear joins heaven and earth." Accounts say he intended 18 towers of varying heights: 12 bell towers for the 12 apostles; four for the evangelists; one to rise over a dome devoted to Mary; and ultimately, the central spire dedicated to Jesus, intended as the tallest religious tower in the world, at 558 feet.

I climb the steeply spiraling stairs up 342 steps in a circular passageway that is less than two feet wide in places. Hoofing up the vertical helix, the turns of the tower give me a chance to contemplate the twists of Gaudí's imagination. There are narrow windows and little parapet balconies to create my own juxtapositions of his wide-ranging art. I can see details up close - like a six-foot conch seashell and a snail, which are his contemporary gargoyles. I can also read phrases like Sursam corda ("Lift up your hearts"), brightly colored saints' names, and key concepts like Sacrificia in large red letters. It reminds me that Gaudí worked on the Sagrada Familia for 43 years of his life, living monastically the last 12 years, dedicated solely to this monument.

In a test of faith for any claustrophobic, I must climb single file, and every person up the line who pauses to pose for his or her perfect picture creates a stop. As I wait, I think about how Gaudí had to build in stops and starts because of politics, his other amazing projects, and because of the commitment that this "cathedral for the poor" would be funded only through "alms and donations."

"The top" is a short walkway between towers, with people going up one tower and down the other. It feels like I am in a transitional aerial epicenter with gorgeous views of Barcelona's bold architecture, embracing mountains and port, and the church all around and below me. It's hard to imagine that when the Sagrada Familia broke ground, it was on land outside the city walls, in a new district called the Eixemplo. Gaudí intended the towering building to be "a lighthouse, the first thing sailors see when coming into port." Now, even without all the lights inside that he planned, it is a monument by which tourists can navigate the city. And I wonder if Gaudí ever imagined that hundreds of thousands of nonsailors would see the Mediterranean Sea from his towers.

The colored fruits also in view were designed by Japanese sculptor Etsuro Sotoo to represent the seasons of the year. They are so large and bright, I laugh with delight. They also represent "the fruits of your labor, inspired by the Holy Spirit," and it seems appropriate to see them from the ground, and then climb up high to this little bridge in the sky that shares the view with other Gaudí towers and aspiring construction cranes.

From here I can see parts of the Glory facade, which will have the largest towers when finished and will portray joys, glories, and divinity to complete the stone storytelling of Christ's life, but also of the life and death of man. It will be the main entrance and is mostly unfinished and draped when I visit. Unlike the other sides of the Sagrada Familia, it no longer has the spacious land offset as originally intended. Buildings were allowed to go up on the valuable real estate nearby, but my guide says the edifices I see across the street will all come down, and residents and stores will relocate when the time comes.

Throughout their stretch upward, the bell towers have slanted vents for light, air, and sound. Gaudí wanted the whole city to "see the light" and hear the music he loved. Our guide thinks the last thing the builders will do for the church is to install 12 large organs whose music will be piped up and out - and heard all over the city.

Gaudí's forms and shapes, and plays with light and sound, tease the imagination more as an unfinished project. Possibilities stilltower.

The current head architect, Jordi Bonet (whose father worked alongside Gaudí as his assistant), says the Sagrada Familia is just over 50 percent complete now. There are domes, vaults, towers, and aisles that future visitors can watch being built. He says he is often asked by worried people when the building will be done. Gaudí was often asked the same question almost a century earlier and replied, “My client is not in a hurry.” No answer could be more appropriate.