San Clemente – Underground Rome Galore!

Underground Rome begins with the Church of San Clemente. After all, it is the oldest site of its kind in Rome! In 1857, Irish Dominican Friar Joseph Mullooly (who lived in the monastery next to the church) began the excavations. Why? A foreign delegation had petitioned the Dominicans to search for an eastern saint’s remains on church grounds.  Although the saint’s burial eluded Mullooly, he did uncovered ancient Rome galore beneath the modern church.

By the way, the “modern” church that Mullooly dug under dates to the 1100s.  But it was partially redecorated in the “very modern” 1600s…! Its original apse mosaics and sumptuous marble inlaid floor are as old as they are beautiful.  A detail of the mosaic is seen in the picture.

apse mosaic from the 1100s in the Church of San Clemente

A Litte Less Than 20 Feet Under San Clemente

But enough dawdling at ground level!  Let’s join Mullooly about twenty feet underground. There he made one of the most unique and interesting discoveries of his time. At what was ground level centuries earlier, he found a Christian basilica dating to circa 350 A.D.  Sure, it is not the first Christian church to be built in Rome after Emperors Licinius and Constantine’s Religious Tolerance Act of 313 A.D.  But it is among the first!

Used for hundreds of years, the church boasts frescoes from shortly after the year 1000. Wealthy donor Maria Macellaria (Mary the Butcher) and her husband paid for them. On one hand, bad timing! Because soon that, the church was abandoned, back-filled, and rebuilt on a higher ground level.  On the other, the frescoes have survived exactly because they were buried! And we will discuss one or two of them (like the one in the picture).

Thirty-five Feet under San Clemente We’ll Stroll around the First Century A.D.


Mullooly didn’t stop there! His curiosity drove him to dig another twenty feet underground. Having reached the first century A.D., he found two imperial surprises. The first was a private home with a mithraeum. This was the chamber or sanctuary where Romans worshiped the ancient Persian god of light and justice, Mithras.  (The Mithraeum can been seen in the picture.)  What was Mithras doing in Rome?  Although scholars debate just how early Mithras-worship infiltrated the city, Roman soldiers stationed in foreign lands and foreign soldiers being stationed throughout the empire contributed to its rapid spread.  In fact, imperial Rome is full of Mithraic sanctuaries.  But most of them are closed to the public.  Luckily, we can visit the one under Saint Clement’s Church!

Mullooly’s second discovery was a sprawling utilitarian building. While some scholars argue that it was imperial Rome’s mint, others say it was a warehouse. Both it and the home with the mithraeum are open to the public.  How exciting!

Practical Information and Ideas

You’ll time travel during the San Clemente Underground Rome tour with Daniella!  And the experience will help you (and your kids) put multiple moments in Roman history into perspective. The visit generally lasts a little less than three hours. Given your interests, it can be paired up with myriad other sites. For example, Vicus Caprarius is an excellent add-on, if you want to continue the underground theme and don’t mind a quick taxi ride. Otherwise, the tiny underground Rome site called the Fountain under Via Annibaldi is in the immediate vicinity of Saint Clement’s. (Please remember it requires a special permission to access.) Finally, consider pairing San Clemente up with other nearby must-sees (like the Colosseum or the Forum).

For more information about the church, visit its official website Tickets to the excavations are euro 10 for adults. Depending on their ages, children enter for free or are eligible for discounts.

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