Wow, you learn something new everyday. Although I've been to Rome multiple times for pilgrimages, I am always frustrated to find out that I was right by Saints whom I didn't even know were there.
Take, for instance, one of the Saints we celebrate today, Pope Saint Leo IV. (Today is also the feast of Saint Alesseo (aka Saint Alexis) whom I mentioned 2 years ago.)
I only happend to find out about Pope Saint Leo IV because he is in my Monastic diurnal since he was a Benedictine.
In trying to find out where he was buried, I found that there's litereally a corner in Saint Peter's which is a cornucopia of holy Leos! I knew about Pope Saint Leo the Great's tomb in the far back left corner. But what I didn't know was that to the left of Pope Saint Leo the Great's altar is the altar of Our Lady of the Column.
It not only contains the relics of Pope Saint Leo the IV, but also of Pope Saint Leo II and Pope Saint Leo III! And I've been to Mass at the altar of Pope Saint Leo the Great, and here were three other Saints named Leo to my right. Add some more to the list of Saints to visit on my next trip.
You can read about his life at Catholic Encyclopedia:
Pope Saint Leo IV
Papa Sancte Leo IV, ora pro nobis.