Holy Hand Grenade of Antioch

So my mother and I scuttered around Italy last Spring, and while I was there to tell her about the art, I counted on her to tell me about all the religious iconography, saints' stories, and relics. She was not much help, I'm afraid, but we did get to see quite a few wonderful things in that vein. Today, I stumbled upon this site, which outlines

Where you can venerate
some First Class Relics

I wish I'd had this list before I went. Be sure to consult it when planning your travel.