At a time when Barcelona is grappling with an unprecedented tourist influx that is challenging the idea of what the city should be, the plans for the Sagrada Familia risk deepening social and political divisions. And just like the reconstruction of Notre Dame in Paris, the project to finish the Sagrada Familia has triggered impassioned debates over the proper role of iconic historical buildings in a modern city.

But perhaps the greatest test will be determining its visionary creator’s intentions. “Gaudí left us the path,” says Jordi Faulí, the head architect now charged with the formidable task of completing a church that will have taken more than seven times as long to build as the great pyramid at Giza. “Sometimes, though, we’ve had to work hard to find it.”