Researchers spent the next three months opening the airtight box and preserving its contents.

Among them was a small case of wax blessed by the Pope that served to protect against mishaps, said Rev. Ruben Avila, rector of the cathedral.

Also inside was an engraving of Saint Barbara, a Roman Catholic martyr associated with lightning whose image served as "a religious lightening rod, to protect against damage," said archaeologist Xavier Cortes, director of historic buildings for the National Council of the Arts and Culture.