Rome's Coolest Undergrounds: What Not to Miss Beneath the City

Rome has a whole other city hiding under its feet. Ancient streets beneath fountains, Roman houses under churches, stadiums under piazzas, and catacombs hidden underground beyond the city walls.

Some underground sites are quick and easy, like Trevi Underground or Piazza Navona’s Stadium of Domitian. Others are more layered, atmospheric, or history-packed, like San Clemente, the Catacombs of Domitilla, and the Case Romane del Celio.

So if you’re wondering which underground experience fits your interests best, start here. We’ll guide you through what makes each one special, and help you choose where to go down first. 

Let’s head down. 

(Psst: More into spooky tunnels, martyr legends, and early-Christian chills? Slide over to our full Catacombs guide). 

1. Vicus Caprarius

2. San Clemente

3. Catacombs of Domitilla

4. Underground Trastevere

5. Stadium of Domitian

6. Case Romane del Celio

7. Colosseum Underground

1. Vicus Caprarius

For: Hidden-history hunters, aqueduct nerds, and anyone curious about the ancient ruins tucked just beside the Trevi Fountain.

Tossed a coin in the Trevi? Nice. Now slip around the corner and duck underground: you’ll find Vicus Caprarius, a sunken Roman insula uncovered when modern renovations accidentally struck history gold. 

Think crumbled walls, a private cistern, and water still flowing from the Aqua Virgo - yep, the very aqueduct feeding the Trevi above. 

Quiet, compact, and seriously cool, it’s a secret slice of ancient Rome hiding in plain sight. 

Time needed: 40 minutes

Tip: Look for the signs on the side streets near Trevi - it’s easy to miss.

Vibe: Tucked-away. Calm. Surprisingly intimate.

2. Basilica di San Clemente al Laterano

For: Time travellers, underground adventurers, and anyone who loves peeling back Rome’s layers.

This isn’t just one church - it’s three, layered like Rome’s most sacred lasagna. 

At street level? A 12th-century basilica covered in glittering mosaics. Below that? A 4th-century church, complete with colourful frescoes. And deeper still? A 1st-century Roman house and a full-on Mithraic temple. 

Bonus: an ancient stream still runs beneath it all - a 2,000-year-old echo from the city’s past.

Time needed: 1 hour

Tip: Don’t rush the floor upstairs - San Clemente’s cosmatesque floor is a masterpiece in its own right.

Vibe: Layered. Mystical. Quietly mind-blowing.

3. Catacombs of Domitilla

For: Early-Christian history lovers, tunnel wanderers, and anyone who likes their Rome with a side of goosebumps. 

Forget marble columns and sunny piazzas for a moment. The Catacombs of Domitilla take you underground into a different Rome: quiet corridors, ancient tombs, early Christian symbols, and frescoes still holding on after all these centuries. 

And yes, there’s a basilica too. Partly above ground, partly tucked into the earth, it’s the perfect warm-up act before the catacombs pull you fully below. 

Time needed: 1.5 hours

Tip: Bring a light jacket - catacombs stay cool even when Rome is melting above ground.

Vibe: Quiet. Sacred. Slightly spine-tingly.

4. Underground Trastevere

For: Curious wanderers, church lovers, and anyone who wants Trastevere with a secret lower level. 

Trastevere is all ivy, cobblestones, aperitivo, and golden evening light. But under its postcard surface, there’s another story: early Christian spaces, ancient remains, and buried chapels. 

This is the underground experience for those who like their history mixed with neighbourhood atmosphere. You get the charm of Trastevere above ground, then the thrill of discovering what’s tucked beneath it. 

Less blockbuster, more hidden-door energy. 

Time needed: 2 hours

Tip: Do this one if you want an underground visit that still feels very “Rome neighbourhood walk”.

Vibe: Local. Atmospheric. Unexpected. 

5. Stadium of Domitian

For: Sports fans, history diggers, and those curious about Rome’s old-school entertainment venues.

Today? Piazza Navona is all fountains, street artists, and gelato. But 2,000 years ago? It was a roaring stadium packed with crowds, cheers, and toga-side drama.

Step below the piazza and you’ll find the remains of the Stadium of Domitian, Rome’s first permanent venue for athletic competitions. Once you know what was here, Piazza Navona’s long oval shape suddenly makes perfect sense. 

Time needed: 40 minutes

Tip: Perfect if you want an underground site that pairs easily with fountains, piazzas, and a walk through the historic centre.

Vibe: Classic. Unexpected. Ancient adrenaline.

6. Case Romane del Celio

For: Secret-spot hunters, history geeks, and anyone into everyday ancient life. 

Hidden beneath the Caelian Hill, these ancient Roman homes are the real deal: multi-storey homes, storerooms, a private shrine, even a wine cellar - all wrapped in frescoes still popping after more than 1,500 years.

Totally unbothered by the tourist trail, this gem isn’t trying to impress - which makes it all the more impressive.

This one is not about emperors and arena spectacles. It’s about colours, private devotion, and the strange thrill of standing inside someone's ancient home.

Time needed: 1 - 1.5 hours

Tip: Slow down. It’s rich in tiny, fascinating details.

Vibe: Intimate. Authentic. Seriously underrated. 

7. Colosseum Underground

For: Gladiator super fans, ancient Rome geeks, and anyone who loves a good backstage pass. 

Think the arena floor was wild? Wait until you see what’s underneath. 

Trapdoors, animal cages, muscle-powered elevators - this was the hidden engine running the spectacle from the shadows.

The underground is where the Colosseum flips from dusty ruin to a living, breathing arena: sweat, drama, engineering, and total time-travel chills. 

Time needed: 3 hours (guided tours only)

Tip: Slots fill up fast, so plan ahead.

Vibe: Thrilling. Ingenious. Big blockbuster energy. 

More Underground Sites Worth Knowing

Rome has plenty more hiding below the surface, from bone-lined chapels to buried palaces and hard-to-book necropolises. Here are a few more underground stops worth keeping on your radar:

The Capuchin Crypt is the macabre one: bones, chapels, and a very Roman reminder that time comes for everyone. Not exactly ancient ruins, but unforgettable for sure.

The Vatican Necropolis, also known as the Scavi Tour, takes you deep beneath St. Peter's Basilica into a Roman burial ground linked to the tomb of St. Peter. Fascinating, but very limited and tricky to book.

The Domus Aurea is Nero's buried golden palace: vast, strange, and still being studied. Complete with a VR-experience which lets the old palace rise around you again, it's one of the most extraordinary underground experiences in Rome when open to visitors.

A Quick Match-Up:

Still torn? Here's the fast version:

> Short on time? Choose Trevi Underground or Piazza Navona Underground

> Want the best "Rome is built in layers" moment? Go for San Clemente Underground

> Curious about early Christianity and ancient burial tunnels? Choose the Catacombs of Domitilla

> Want something atmospheric, local, and a little unexpected? Try Underground Trastevere

> Into ancient homes, frescoes, and everyday Roman life? Pick the Case Romane del Celio

> Want the blockbuster underground experience? Book the Colosseum Underground

Craving more underground mysteries? Dive into our full Catacombs guide - your quick way to compare Rome’s famous tunnels and find the perfect one for your vibe.