Long-gestating construction on Barcelona’s famed Sagrada Familia reached a milestone this week when workers completed the upper section of its highest tower—a monument to Jesus Christ that makes the fantastical building the tallest church in the world.Work on the architect Antoni Gaudí’s masterpiece commenced in 1882, and only one of its towers reached completion by the time he died in 1926, at the age of 73.But as reported by The Guardian, the chief architect for the project called last Friday—when a 56-foot cross was lifted into position—“a joyful day, wonderful for all the people who have made it possible.” Construction is expected to continue for a decade or so, but The Guardian called it “nevertheless a day full of emotion for a city that has lived with Gaudí’s unfinished work for generations.”As noted by Popular Science, “The cross uses a combination of glass, ceramic tile, and stone materials from the Spanish region of Catalonia, but was built in sections by artisans in Germany. From there, each piece was transported by ferry and truck to Barcelona, where crane crews carefully erected the final components of the basilica’s exterior works. The structure is large enough to accommodate an interior spiral staircase, and is intended to honor Gaudí’s original goal of letting the cross shine day and night.”A ceremony to mark the completion of the tower is scheduled for June 10, in a year that marks the centennial of Gaudí’s death. It is also coincides with Barcelona’s being designated as UNESCO’s World Capital of Architecture for 2026. The city will also host the UIA World Congress of Architects from June 28 to July 2. Earlier this month, an exhibition space for contemporary art opened in Casa Batlló, another Gaudí-designed landmark and UNESCO World Heritage Site in Barcelona.