The Very Confusing Baths of Diocletian in Rome

This first section is a brief explanation of my Italy blog posts, which were inspired by my 2-week trip to Italy in May, 2025. Feel free to skip this section if you’ve read it before.

Dear Reader, If you read my Italy posts in the order in which they’ve come out, it may seem as though we hopped back and forth all over the country, but I have decided not to write these posts sequentially. I want to write about the things that interest me most, as the spirit moves me. For some topics, I may even combine cities. I hope that by doing so, you’ll find it a lot more interesting than if I just give you a tedious day by day description of our itinerary, as if I were your Aunt Mabel forcing you to sit down and watch all her Super 8 films of the family road trip to Niagara Falls from 1966.

If you have any questions, comments or suggestions about how I’m approaching this travelogue-within-a-blog, please let me know in the comments below!

There are two large ruins of ancient Roman Baths that you can visit in Rome. The Baths of Caracalla and the Baths of Diocletian. Our Rick Steves guidebook gave us the impression that, if you didn’t have time to see both (and we definitely didn’t) there were pros and cons to each. We decided to visit the Baths of Diocletian for the following reasons:

I had visited Diocletian’s Palace in Split, Croatia (and blogged about it here), so I thought it would be fun to see his baths, too.
It is much larger than Carcalla. In fact, it was the largest public bath complex in the Roman Empire.
A Basilica, designed by Michelangelo, had been created in the center of the complex ruins, using much of the ancient structure, which was said to be still discernable.
I’m embarrassed to admit this, but it was closer to a Metro stop.

In retrospect, we might have made the wrong choice. Of all the places we visited in Italy, this was the one place where I spent the entire visit feeling extremely confused. There are several possible reasons for this:

I dropped the ball on my research for this venue.
We had spent the morning riding bikes along the Appian Way in a persistent rain, and while that was fun, I was worn out and soaked through, and we had a lot more planned before the day was over, so time was a’wastin’.
My back was killing me, and I was trying really hard not to show it for Dear Husband’s sake, but I could tell I wasn’t succeeding, so I felt guilty and I wasn’t thinking straight.
We would be leaving Italy the next day, and I had very mixed emotions about that, as I always do at the end of a two-week trip to a foreign country. I missed my dogs. I wanted to sleep in my own bed. But I was dreading the whole 18 hour stretch between Italy and home, and I definitely didn’t want to go back to work, and there was so much to see that I hadn’t seen and odds are high I’ll never see Italy again, and the thought of that still makes me want to cry.
But mostly it’s that the layout of the Baths of Diocletian is freakin’ confusing, and I seemed to be the only one concerned that we’d miss something.

All of that meant I had put an immense amount of pressure upon myself, and I wasn’t in the best frame of mind. And having done my research for this post, it seems that we did, indeed, miss a heck of a lot. That bothers me. But we did see a lot of cool things, too, so it’s still worth blogging about.

Let me start off by telling you that you can find maps of the layout of the original baths all over the place. Here are just a few that I’ve seen. None of them are more than a tiny bit of help, though, as they all require that you to use quite a bit of imagination.

You can also see artists renderings of what the baths must have looked like at various points in history. They really sparked my imagination, and made me hopeful that I’d be seeing a lot of fascinating ruins. That had been the case all over Italy, so this shouldn’t be any different. That was my thinking.

Another gross misconception that I had was that these baths would be like every other archeological site we had seen in Italy. Like Pompeii, for example. You pay your admission, you walk in, and you are certain you’re there, and they make it all but impossible for you to wander off the site without knowing that you’re no longer there.

Nope. What I wasn’t prepared for is that, first of all, a good deal of the Baths of Diocletian are gone without a trace. And the rest are not through one convenient door with an information booth and a handy brochure. To get any sense of the baths at all, you have to visit several different venues.

Part of the baths are run by the National Roman Museum. Then you leave there, and you see part of them in the Basilica of Santa Maria degli Angeli e dei Martiri next door (That’s the one Michelangelo built on the bath grounds). And, most surprising, a good chunk of it is actually the Piazza della Repubblica today. Yup. A big circular Piazza, with cars zipping around its perimeter, and a pretty fountain in the middle. That whole area used to be the theater of the Baths of Diocletian back in the day. The only way you can really tell is by the shape. There are also some cloisters and gardens that are sort of half on, half off what was once the bath property. We got to see the large one, but the small one was closed. Those are the parts of the baths that we saw.

Sadly, even when looking at these things, I never felt certain that I was seeing the baths, and if I was, it was impossible to know which part. So yeah. Confused was the order of the day. And I don’t like being confused when I’m seeing someplace for the one and only time. This may have been one of the few times we would have benefitted from hiring a guide.

Among the many things we didn’t see include a ton of rooms/buildings in the museum that we overlooked or that I was in too much pain to walk to or that were closed, including the small cloister/charterhouse. There was also another church, San Bernardo alle Terme (which I only learned about just now) which resides in one of its corner towers with a dome. And there was an Octagonal Hall with a dome that was converted into a planetarium for about 60 years, but that closed in the 80’s, and now the space is only used for the occasional art exhibition. Sadly, it was closed while we were there. There’s also a restaurant called Terme di Diocleziano that’s actually built into one of the corner towers of the old baths that I wish I had known about. I can’t recommend it personally, as I’ve never eaten there myself, but it seems to get really good reviews.

So, with all those caveats, let’s get started.

At a time when Emperor Maximian was the emperor of the western part of the empire, and Diocletian was the emperor of the eastern part, Maximian decided to have these baths built for the people of Rome and consecrated the project to his co-emperor. The whole place took 8 years to build, between 298 and 306AD, and they used 10,000 to 40,000 slaves to do so (depending on whom you believe). Ironically, it wasn’t completed until after Diocletian was the first Roman emperor to voluntarily abdicate. He went home to his palace in Split, Croatia, and most likely never set foot in these baths after they were fully completed.

This dedication plaque for the baths really caught my eye. How on earth could they figure out what the whole thing said from so few fragments? Well, it seems that there were several plaques throughout the baths that said the same thing, so they could gather a bit here and a bit there. Also, the full text is known thanks to a transcription made between the 8th and 9th centuries by an anonymous pilgrim. The transcription was preserved in a manuscript at Einsiedeln Abbey, Switzerland. The dedication reads as follows:

Diocletian and Maximian, Augusti seniores and fathers of the emperors and Caesars, together with the Augusti Constantius and Maximian, and with the Caesars Severus and Maximinus, dedicated the auspicious Baths of Diocletian to their Romans -suis Romanis. Upon his return to Rome from Africa, Maximian commissioned the Thermae and consecrated them to his co-emperor Diocletian, defined as his brother. Maximian purchased many buildings -coemptis aedificiis- to construct this huge and mighty work -pro tanti operis  magnitudine- and furnish it with all manner of ornament-omni cultu perfectas.

The entire complex of the Baths of Diocletian covered about 32 acres. The walls that surrounded it were 1233 feet long by 1184 feet wide. Most of the walls no longer stand, but you can see a few sections here and there. The complex included a theatre, two libraries, two circular halls, the frigidarium (cold pool), tepidarium (warm pool), and the caldarium (hot pool). In addition, there was a natatio, an outdoor pool the size of three Olympic-sized swimming pools. There were also saunas, oiling rooms, two large outdoor gymnasiums, two octagonal halls, changing rooms, laundry facilities, places for lectures and poetry readings, a garden, art galleries, lounging rooms, vendors and reading rooms. Some say there were also brothels, but others make no mention of them.

The baths could accommodate 3,000 people at a time. It often saw 10,000 people a day. Women and children generally went earlier in the day, and the men went after work. If men and women were at the baths at the same time, they were in separate pools.

Now, if you do any serious reading about the baths, you will find that some people depict them as being sparklingly clean with turquoise blue water. That’s not very realistic at a time without the pool chemicals we have today. On the other hand, some say these baths were fetid swamps of disease and filth. I don’t buy that, either. First of all, I doubt people would have kept coming back if they were that disgusting. Second, if the Romans knew nothing else, they knew about waterflow and proper drainage. In fact, we now believe that the used water from the natatio was then diverted to latrines, so it was definitely replaced regularly.

But let’s face it: that was a lot of people passing through every day. At a time before vaccines or antibiotics, and when plagues were rampant. And they did like to use oil on their skin, and get sweaty from exercise, so the water, despite flowing, probably did get murky. Walking barefoot on floors were thousands of others a day did so probably exposed people to skin infections as well.

But it was also a beautifully appointed, open and airy place in which to socialize. That was probably a world of difference from the average Roman’s living situation. So despite the risks, these baths would have been awfully hard to resist.

Originally these baths were lined with marble, mosaics, and vibrant frescoes, and the exteriors of the buildings were white stucco. After having invested so much money in making the place so luxurious, it’s hard to imagine the administration being okay with it turning into a fetid swamp. But we’ll never know for sure.

Now, what you see, in every area except the basilica, is mostly brick and concrete with a few chunks of marble here and there that the looters of the Middle Ages were unable to make off with. It is believed that there were also 3,200 marble seats in the complex, and all of them have disappeared. The complex was in use until around the year 537AD, when the invading Ostrogoths cut off the aqueducts to Rome, thus eliminating the water supply to the city.

1n 1561, Pope Pius IV decided to build a basilica with a charterhouse attached, to commemorate the Christian martyrs who may (or may not) have died during the construction of the baths. Michelangelo planned the church, using both the frigidarium and the tepidarium areas without altering the original structures, which were still standing. He also created a small cloister where 1/3^rd of the outdoor pool once stood. In addition, he designed the large cloister/monastery, only half of which is on the bath grounds, and it is said that he personally planted the cypress trees that still stand there. Work on the large cloister was done in 1565.

In 1575, Pope Gregorius XIII had several halls of the baths converted into warehouses to store grain and olive oil, and one was used as a bakery. This practice went on until 1816. Then, some of it was converted into an orphanage and poorhouse for women.

The National Roman Museum’s collection of sculptures, tombs, frescoes, deep reliefs, and mosaics were not all found in the baths, and that’s unfortunate, because it adds to the confusion. The dedication plaque mentioned above is definitely from the baths, as are these decorative tiles. Everything else could be from anywhere in the city. We missed a lot of rooms in this museum, and now I deeply regret it.

The large Cloister and Carthusian Monastery is the largest in Italy. Each side of it is 300 feet long, and there are a total of 100 pillars. It did not exist when the baths existed. In fact, part of the ruins were demolished to make way for it.

Pope Pious IV tasked the Carthusian Monks to care for the Baths of Diocletian, but for them to live there, they needed a charterhouse. The monks wore all white hooded robes, and they lived in seclusion, even from one another. They lived there until it was abandoned in 1884. The order still exists. To this day they live in silence, they work, and they reside in individual cells that line the edges of cloisters such as this one.

Within the large cloister are about 400 statues, decorative architectural objects and sarcophagi. Again, most of these are not actually from the ruins of the baths. But wow, were they impressive. (And we had a lot of fun imitating some of the funnier faces.) The 4 most startling sculptures were right in the center of the grounds. They were originally in Trajan’s Forum, and are at least 1900 years old. They don’t look like any other Roman sculptures that I’ve ever seen.

After we left the cloister portion of the museum, we went to the Church of Santa Maria degli Angeli e dei Martiri. When you walk into this church, you’re actually entering what used to be the tepidarium of the baths, and the larger room beyond was the frigidarium. And the most amazing thing is that the vaulted roofs, which are 75 feet above the floor, are the originals, as are 4 of the red granite pillars, which are 5 feet wide and 45 feet tall. The other 4 are actually well painted reproductions. The marble capitals atop many of the columns are the 1700-year-old originals, as well.

Another cool thing about this church is that there is quite a bit of contemporary art in it, and it also houses Rome’s beautiful Meridian line/double sundial, built in 1702. It is bronze, and is embedded in the marble floor, and every day at noon, as long as the sun is shining, it will hit somewhere along this line. Romans relied on it for setting their clocks and calendars, and for determining what day Easter would fall on, until 1846. It even tells you where you are, astrologically, within the year. But they were smart to choose such an ancient, well-settled building for their line. Italy is earthquake prone, so it would be easy for a meridian line to be thrown off. But this meridian line is still accurate to this very day. Oh, and their organ is absolutely gorgeous.

Also, an intriguing bit of information about this church is it is surrounded by old rooms that are no longer used, but were used as recently as 1911. In fact, a really eccentric American sculptor named Moses Jacob Ezekiel lived in one of these rooms and used it as his studio from the 1870’s to 1911. He had fought for the confederacy in the Civil War, then went to Berlin to learn his art, before coming to Rome to somehow settle in at the baths.

He held an open house every Friday afternoon, a sort of elite salon, that was a must-attend for anyone of significance who visited Rome. Live music and refreshments were provided. Some of his guests included Queen Margherita of Italy, General Ulysses S. Grant, Franz Liszt, Emperor Wilhelm II of Germany, Mark Twain and Richard Wagner.

Finally, the authorities threw him out because they were holding the Exposition of 1911 at the baths, to showcase Roman art and architecture. But he did not go quietly. He threatened to shoot the authorities where they stood. In the end they got him to relocate, but due to fuel shortages during WWI, he couldn’t heat this new studio. He developed pneumonia, and passed away in 1917 at the age of 72.

While I can blame Ezekiel for his lifelong support for the Lost Cause of the Confederacy and all that it symbolized, I can’t blame him for not wanting to leave the baths. Despite being confusing, they are also fascinating, and in the end, I had no regrets for having visited them. I just wish I had done more homework and had more time to see everything.

I’ll leave you with this 3 minute video montage from the videos Dear Husband took during our visit. Photos can’t convey how vast the Baths of Diocletian were. Videos do a slightly better job. Enjoy!