Valencia
On 9 July 2006, during Mass at Valencia's Cathedral, Our Lady of the Forsaken Basilica, Pope Benedict XVI used, at the World Day of Families, the Santo Caliz, a 1st-century Middle-Eastern artifact that some Catholics believe is the Holy Grail. It was supposedly brought to that church by Emperor Valerian in the 3rd century, after having been brought by St. Peter to Rome from Jerusalem. The Santo Caliz (Holy Chalice) is a simple, small stone cup. Its base was added in Medieval Times and consists of fine gold, alabaster and gem stones.

Q: Which pope used the Santo Caliz for mass in Valencia?
Benedict XVI