The Sagrada Familia basilica in Barcelona, Spain, is one of the world's most visited landmarks. But according to Josep Turull, the priest in charge of the basilica, many people do not notice its most fascinating features. He said that even after eight years in his role, he still discovered something new in the basilica almost every day.

Before Pope Leo XIV's visit on June 11, 2026, Turull gave reporters a private tour of the basilica. He pointed out several interesting details. One was a mysterious numbered grid on the Façade of the Passion, a large outside wall showing scenes from Jesus' final days before his death. Adding the numbers in any direction produces 33, the age of Jesus when he died on the cross.

The basilica also has a quieter side. Below the main floor is a small underground chapel. People attend Mass there away from the crowds of tourists. Mass is a Catholic church service. The chapel is also where architect Antoni Gaudí is buried. Gaudí, who died in 1926 after being hit by a streetcar, may one day be named a saint by the Vatican.

On the upper floors, a private room holds beautiful oak cabinets designed by Gaudí and the clothing worn by past popes. Pope Leo XIV was expected to use this room before celebrating Mass.