Photos: Treasure of San Gennaro

The Treasure of San Gennaro, one of the most important and valuable collections of religious art, has travelled outside its native Naples for the first time, giving Rome a glimpse of the centuries-long devotion to the 3rd century martyr.

The Rome Foundation Museum exhibit, which opened Wednesday and runs through Feb. 16, features the empty reliquary that holds the saint's purported blood. According to legend, the blood "miraculously" liquefies during certain religious ceremonies.

Highlights also include the bejeweled San Gennaro necklace and a bishop's miter, made of gold-plated silver and adorned with 3,326 diamonds, 164 rubies and 198 emeralds. The necklace contains gems and jeweled crosses that were donated by Napoleon and members of European royalty over the centuries, a reflection of the immense popularity of the saint. — The Associated Press